ORCID Profile
0000-0001-9494-400X
Current Organisations
Australian National University
,
University of Adelaide
,
Julius-Kuhn-Insitute
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Publisher: Springer Science and Business Media LLC
Date: 2009
Publisher: Elsevier
Date: 2012
Publisher: American Physical Society (APS)
Date: 23-03-2011
Publisher: Springer Science and Business Media LLC
Date: 10-2020
DOI: 10.1186/S12870-020-02332-4
Abstract: A family of genes designated as the Zinc finger A20/AN1 Transcription factors encoding stress-associated proteins ( SAP ) are well described in Arabidopsis and rice, and include 14 AtSAP and 18 OsSAP genes that are associated with variable tolerances to multiple abiotic stresses. The SAP gene family displays a great ersity in its structure and across different plant species. The aim of this study was to identify all HvSAP genes in barley ( Hordeum vulgare L.), to analyse the expression of selected genes in response to salinity in barley leaves and develop SNP marker for HvSAP12 to evaluate the association between genotypes of barley plants and their grain yield in field trials. In our study, 17 HvSAP genes were identified in barley, which were strongly homologous to rice genes. Five genes, HvSAP5 , HvSAP6 , HvSAP11 , HvSAP12 and HvSAP15 , were found to be highly expressed in leaves of barley plants in response to salt stress in hydroponics compared to controls, using both semi-quantitative RT-PCR and qPCR analyses. The Amplifluor-like SNP marker KATU-B30 was developed and used for HvSAP12 genotyping. A strong association (R 2 = 0.85) was found between KATU-B30 and grain yield production per plant of 50 F 3 breeding lines originating from the cross Granal × Baisheshek in field trials with drought and low to moderate salinity in Northern and Central Kazakhstan. A group of HvSAP genes, and HvSAP12 in particular, play an important role in the tolerance of barley plants to salinity and drought, and is associated with higher grain yield in field trials. Marker-assisted selection with SNP marker KATU-B30 can be applied in barley breeding to improve grain yield production under conditions of abiotic stress.
Publisher: Czech Academy of Agricultural Sciences
Date: 31-12-2011
DOI: 10.17221/3260-CJGPB
Publisher: The Optical Society
Date: 24-09-2009
DOI: 10.1364/OE.17.018196
Publisher: Wiley
Date: 02-2003
Publisher: Springer Science and Business Media LLC
Date: 2012
Publisher: Elsevier BV
Date: 09-2004
Publisher: Wiley
Date: 02-08-2006
Publisher: MDPI AG
Date: 24-05-2020
Abstract: Multi-environment trial studies provide an opportunity for the detailed analysis of complex traits. However, conducting trials across a large number of regions can be costly and labor intensive. The Australian National Variety Trials (NVT) provide grain yield and protein content (GPC) data of over 200 wheat varieties in many and varied environments across the Australian wheat-belt and is representative of similar trials conducted in other countries. Through our analysis of the NVT dataset, we highlight the advantages and limitations in using these data to explore the relationship between grain yield and GPC in the low yielding environments of Australia. Eight environment types (ETs), categorized in a previous study based on the time and intensity of drought stress, were used to analyze the impact of drought on the relationship between grain yield and protein content. The study illustrates the value of comprehensive multi-environment analysis to explore the complex relationship between yield and GPC, and to identify the most appropriate environments to select for a favorable relationship. However, the NVT trial design does not follow the rigor associated with a normal genotype × environment study and this limits the accuracy of the interpretation.
Publisher: MDPI AG
Date: 11-2019
Abstract: Grain protein content (GPC) is a key quality attribute and an important marketing trait in wheat. In the current cropping systems worldwide, GPC is mostly determined by nitrogen (N) fertilizer application. The objectives of this study were to understand the differences in N response between high and low GPC wheat genotypes, and to assess the value of biomass growth analysis to assess the differences in N response. Six wheat genotypes from a range of high to low GPC were grown in low, medium and high N, under glasshouse conditions. This experiment was designed around non-destructive estimation of biomass using a high throughput image-based phenotyping system. Results showed that Spitfire and Mace had higher grain N% than Gazelle and QAL2000, and appeared to demand more N to grow their biomass. Moreover, at low N, Spitfire grew faster and achieved the maximum absolute growth rate earlier than high N-treated plants. High grain N% genotypes seem able to manage grain N reserves by compromising biomass production at low N. This study also indicated the importance of biomass growth analysis to show the differences in the N responsiveness of high and low GPC wheat.
Publisher: Springer Science and Business Media LLC
Date: 21-03-2006
DOI: 10.1007/S00122-006-0252-Z
Abstract: Improving the end-use quality of wheat is a key target for many breeding programmes. With the exception of the relationship between glutenin alleles and some dough rheological characters, knowledge concerning the genetic control of wheat quality traits is somewhat limited. A doubled haploid population produced from a cross between two Australian cultivars 'Trident' and 'Molineux' has been used to construct a linkage map based largely on microsatellite molecular makers. 'Molineux' is superior to 'Trident' for a number of milling, dough rheology and baking quality characteristics, although by international standards 'Trident' would still be regarded as possessing moderately good end-use quality. This population was therefore deemed useful for investigation of wheat end-use quality. A number of significant QTL identified for dough rheological traits mapped to HMW and LMW glutenin loci on chromosomes 1A and 1B. However, QTL associated with dough strength and loaf volume were also identified on chromosome 2A and a significant QTL associated with loaf volume and crumb quality was identified on chromosome 3A. A QTL for flour protein content and milling yield was identified on chromosome 6A and a QTL associated with flour colour reported previously on chromosome 7B was confirmed in this population. The detection of loci affecting dough strength, loaf volume and flour protein content may provide fresh opportunities for the application of marker-assisted selection to improve bread-making quality.
Publisher: Springer Science and Business Media LLC
Date: 03-1998
Abstract: Restriction fragment length polymorphisms (RFLPs) have been used to characterise the genetic ersity of wheat (Triticum aestivum) germplasm. One hundred and twenty-four accessions comprising all major Australian wheat varieties and lines important for breeding purposes were assayed for RFLPs with clones of known genetic location and selected to give uniform genome coverage. The objectives of this study were to determine RFLP-based genetic similarity between accessions and to derive associations between agronomically significant traits and RFLP phenotypes. Ninety-eight probes screened against genomic DNA digested with five restriction endonucleases detected a total of 1968 polymorphic fragments. Genetic similarity (GS) calculated from the RFLP data ranged from 0.004 to 0.409 between accessions, with a mean of 0.18. Cluster analysis based on GS estimates produced four groupings that were generally consistent with available pedigree information. Comparisons of the RFLP phenotypes of accessions containing disease resistance genes present on introgressed alien segments enabled the identification of specific alleles characteristic of these regions. Associations were derived for a range of stem-rust, leaf-rust and yellow-rust resistance genes. These results suggest that RFLP analysis can be used for the characterisation and grouping of elite breeding material of wheat and RFLP profiling can identify chromosome segments associated with agronomic traits.
Publisher: Springer Science and Business Media LLC
Date: 23-08-2007
DOI: 10.1007/S00122-007-0629-7
Abstract: Grain yield forms one of the key economic drivers behind a successful wheat (Triticum aestivum L.) cropping enterprise and is consequently a major target for wheat breeding programmes. However, due to its complex nature, little is known regarding the genetic control of grain yield. A doubled-haploid population, comprising 182 in iduals, produced from a cross between two cultivars 'Trident' and 'Molineux', was used to construct a linkage map based largely on microsatellite molecular makers. 'Trident' represents a lineage of wheat varieties from southern Australia that has achieved consistently high relative grain yield across a range of environments. In comparison, 'Molineux' would be rated as a variety with low to moderate grain yield. The doubled-haploid population was grown from 2002 to 2005 in replicated field experiments at a range of environments across the southern Australian wheat belt. In total, grain yield data were recorded for the population at 18 site-year combinations. Grain yield components were also measured at three of these environments. Many loci previously found to be involved in the control of plant height, rust resistance and ear-emergence were found to influence grain yield and grain yield components in this population. An additional nine QTL, apparently unrelated to these traits, were also associated with grain yield. A QTL associated with grain yield on chromosome 1B, with no significant relationship with plant height, ear-emergence or rust resistance, was detected (LOD > or =2) at eight of the 18 environments. The mean yield, across 18 environments, of in iduals carrying the 'Molineux' allele at the 1B locus was 4.8% higher than the mean grain yield of those lines carrying the 'Trident' allele at this locus. Another QTL identified on chromosome 4D was also associated with overall gain yield at six of the 18 environments. Of the nine grain yield QTL not shown to be associated with plant height, phenology or rust resistance, two were located near QTL associated with grain yield components. A third QTL, associated with grain yield components at each of the environments used for testing, was located on chromosome 7D. However, this QTL was not associated with grain yield at any of the environments. The implications of these findings on marker-assisted selection for grain yield are discussed.
Publisher: Springer Science and Business Media LLC
Date: 10-1998
Publisher: Wiley
Date: 11-11-2009
Publisher: Elsevier BV
Date: 2002
Publisher: Wiley
Date: 06-07-2016
DOI: 10.1111/PBI.12432
Abstract: Plants respond to abiotic stresses by changes in gene regulation, including stress-inducible expression of transcriptional activators and repressors. One of the best characterized families of drought-related transcription factors are dehydration-responsive element binding (DREB) proteins, known as C-repeat binding factors (CBF). The wheat DREB/CBF gene TaRAP2.1L was isolated from drought-affected tissues using a dehydration-responsive element (DRE) as bait in a yeast one-hybrid screen. TaRAP2.1L is induced by elevated abscisic acid, drought and cold. A C-terminal ethylene responsive factor-associated hiphilic repression (EAR) motif, known to be responsible for active repression of target genes, was identified in the TaRAP2.1L protein. It was found that TaRAP2.1L has a unique selectivity of DNA-binding, which differs from that of DREB activators. This binding selectivity remains unchanged in a TaRAP2.1L variant with an inactivated EAR motif (TaRAP2.1Lmut). To study the role of the TaRAP2.1L repressor activity associated with the EAR motif in planta, transgenic wheat overexpressing native or mutated TaRAP2.1L was generated. Overexpression of TaRAP2.1L under constitutive and stress-inducible promoters in transgenic wheat and barley led to dwarfism and decreased frost tolerance. By contrast, constitutive overexpression of the TaRAP2.1Lmut gene had little or no negative influence on wheat development or grain yield. Transgenic lines with the TaRAP2.1Lmut transgene had an enhanced ability to survive frost and drought. The improved stress tolerance is attributed to up-regulation of several stress-related genes known to be downstream genes of DREB/CBF activators.
Publisher: The Optical Society
Date: 29-05-2015
DOI: 10.1364/OE.23.014903
Publisher: Oxford University Press (OUP)
Date: 09-05-2013
Publisher: Humana Press
Date: 2009
DOI: 10.1007/978-1-59745-427-8_4
Abstract: Large insert libraries are valuable tools for the positional cloning of genes of interest, physical mapping of chromosomes, comparative genomics, and molecular breeding. There are five types of large DNA insert libraries: cosmid, yeast artificial chromosomes (YACs), bacteriophage P1, bacterial artificial chromosomes (BACs) and P1-derived artificial chromosomes (PACs) libraries. Of these libraries, BAC libraries are the most widely used due to their ease of manipulation, large insert size, and stability. This chapter reports on a simplified method for plant BAC library construction. This method involves isolation and partial digestion of intact nuclei, selection of appropriate size of DNA via pulsed-field gel (PFG) electrophoresis, elution of DNA from agarose gels, ligation of DNA into the BAC vector, electroporation of the ligation mix into Escherichia coli cells, and estimation of insert sizes. The whole process takes 1-3 months depending on the genome size and coverage required. We have used this method to produce BAC libraries from different plant species including sunolgrass (Phalaris coerulescens L.), barley (Hordeum vulgare L.), lupin (Lupinus angustifolias L.) and rye (Secale cereale L.).
Publisher: Springer Science and Business Media LLC
Date: 02-11-2012
DOI: 10.1007/S00122-011-1740-3
Abstract: In southern Australia, where the climate is predominantly Mediterranean, achieving the correct flowering time in bread wheat minimizes the impact of in-season cyclical and terminal drought. Flag leaf glaucousness has been hypothesized as an important component of drought tolerance but its value and genetic basis in locally adapted germplasm is unknown. From a cross between Kukri and RAC875, a doubled-haploid (DH) population was developed. A genetic linkage map consisting of 456 DArT and SSR markers was used to detect QTL affecting time to ear emergence and Zadoks growth score in seven field experiments. While ear emergence time was similar between the parents, there was significant transgressive segregation in the population. This was the result of segregation for the previously characterized Ppd-D1a and Ppd-B1 photoperiod responsive alleles. QTL of smaller effect were also detected on chromosomes 1A, 4A, 4B, 5A, 5B, 7A and 7B. A novel QTL for flag leaf glaucousness of large, repeatable effect was detected in six field experiments, on chromosome 3A (QW.aww-3A) and accounted for up to 52 percent of genetic variance for this trait. QW.aww-3A was validated under glasshouse conditions in a recombinant inbred line population from the same cross. The genetic basis of time to ear emergence in this population will aid breeders' understanding of phenological adaptation to the local environment. Novel loci identified for flag leaf glaucousness and the wide phenotypic variation within the DH population offers considerable scope to investigate the impact and value of this trait for bread wheat production in southern Australia.
Publisher: Springer Science and Business Media LLC
Date: 28-11-2012
DOI: 10.1038/491678A
Publisher: Public Library of Science (PLoS)
Date: 08-2012
Publisher: Springer Science and Business Media LLC
Date: 11-10-2017
DOI: 10.1038/S41467-017-00945-2
Abstract: The current rate of yield gain in crops is insufficient to meet the predicted demands. Capturing the yield boost from heterosis is one of the few technologies that offers rapid gain. Hybrids are widely used for cereals, maize and rice, but it has been a challenge to develop a viable hybrid system for bread wheat due to the wheat genome complexity, which is both large and hexaploid. Wheat is our most widely grown crop providing 20% of the calories for humans. Here, we describe the identification of Ms1 , a gene proposed for use in large-scale, low-cost production of male-sterile ( ms ) female lines necessary for hybrid wheat seed production. We show that Ms1 completely restores fertility to ms1d , and encodes a glycosylphosphatidylinositol-anchored lipid transfer protein, necessary for pollen exine development. This represents a key step towards developing a robust hybridization platform in wheat.
Publisher: Springer Science and Business Media LLC
Date: 25-11-2020
DOI: 10.1038/S41586-020-2961-X
Abstract: Advances in genomics have expedited the improvement of several agriculturally important crops but similar efforts in wheat ( Triticum spp.) have been more challenging. This is largely owing to the size and complexity of the wheat genome 1 , and the lack of genome-assembly data for multiple wheat lines 2,3 . Here we generated ten chromosome pseudomolecule and five scaffold assemblies of hexaploid wheat to explore the genomic ersity among wheat lines from global breeding programs. Comparative analysis revealed extensive structural rearrangements, introgressions from wild relatives and differences in gene content resulting from complex breeding histories aimed at improving adaptation to erse environments, grain yield and quality, and resistance to stresses 4,5 . We provide ex les outlining the utility of these genomes, including a detailed multi-genome-derived nucleotide-binding leucine-rich repeat protein repertoire involved in disease resistance and the characterization of Sm1 6 , a gene associated with insect resistance. These genome assemblies will provide a basis for functional gene discovery and breeding to deliver the next generation of modern wheat cultivars.
Publisher: Canadian Science Publishing
Date: 10-2013
Publisher: The Optical Society
Date: 08-08-2008
DOI: 10.1364/OL.33.001851
Abstract: We demonstrate experimentally the formation of polychromatic single- and double-charge optical vortex solitons by employing a lithium niobate crystal as a nonlinear medium with defocusing nonlinearity. We study the wavelength dependence of the vortex core localization and observe self-trapping of polychromatic vortices with a bandwidth spanning over more than 70 nm for single-charge and 180 nm for double-charge vortex solitons.
Publisher: Springer Science and Business Media LLC
Date: 10-2020
DOI: 10.1186/S12870-020-02331-5
Abstract: Chickpea is an important legume and is moderately tolerant to salinity stress during the growing season. However, the level and mechanisms for salinity tolerance can vary among accessions and cultivars. A large family of CaRab -GTP genes, previously identified in chickpea, is homologous to intracellular vesicle trafficking superfamily genes that play essential roles in response to salinity stress in plants. To determine which of the gene family members are involved in the chickpea salt response, plants from six selected chickpea accessions (Genesis 836, Hattrick, ICC12726, Rupali, Slasher and Yubileiny) were exposed to salinity stress and expression profiles resolved for the major CaRab -GTP gene clades after 5, 9 and 15 days of salt exposure. Gene clade expression profiles (using degenerate primers targeting all members of each clade) were tested for their relationship to salinity tolerance measures, namely plant biomass and Na + accumulation. Transcripts representing 11 out of the 13 CaRab clades could be detected by RT-PCR, but only six ( CaRabA2 , −B , −C , −D , −E and − H ) could be quantified using qRT-PCR due to low expression levels or poor lification efficiency of the degenerate primers for clades containing several gene members. Expression profiles of three gene clades, CaRabB , −D and −E , were very similar across all six chickpea accessions, showing a strongly coordinated network. Salt-induced enhancement of CaRabA2 expression at 15 days showed a very strong positive correlation (R 2 = 0.905) with Na + accumulation in leaves. However, salinity tolerance estimated as relative plant biomass production compared to controls, did not correlate with Na + accumulation in leaves, nor with expression profiles of any of the investigated CaRab -GTP genes. A coordinated network of CaRab-GTP genes, which are likely involved in intracellular trafficking, are important for the salinity stress response of chickpea plants.
Publisher: IEEE
Date: 06-2009
Publisher: Springer Science and Business Media LLC
Date: 03-1998
Abstract: A dispersed, rye-specific element has been used to isolate clones of rye origin from wheat plants containing only a single rye chromosome arm or segment. In this way a set of 23 YAC clones has been isolated from the short arm of rye chromosome 1 (1RS). This technique was extended to isolate clones from a small region of 1RS that contains a large number of agronomically important genes. The targeted cloning method allowed the isolation of 26 classes of lambda clones representing about 5% of the region. Ten of the lambda clones could be mapped to segments within this region. A third ex le of the application of this technique involved the isolation of clones from a very small but fully functional rye chromosome, the midget chromosome. These clones have allowed the confirmation of the origin of the midget from 1RL, and may provide a tool for the isolation of structural elements of cereal chromosomes. This technique allows the identification of clone libraries for any rye chromosome or chromosome arm, since substitution, addition and translocation lines are available for all rye chromosomes. Furthermore, the technique allows isolation of clones derived from segments of the rye genome recombined into wheat. The method is technically simple and both lambda and YAC libraries can be constructed. Synteny between the genomes of the cereals allows region-specific libraries from rye to be used to target regions of the wheat and barley genomes.
Publisher: European Optical Society
Date: 02-02-2010
Publisher: Springer Science and Business Media LLC
Date: 12-2017
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.PLAPHY.2017.06.004
Abstract: Increased endopolyploidy is important for plant growth and development as well as for adaptation to environmental stresses. However, little is known about the role of reduced endopolyploidy, especially in root systems. In this report, endopolyploidy variations were examined in different types of barley (Hordeum vulgare L.) roots, and the effects of phosphorus (P) deficiency and salinity (NaCl) stress on root endopolyploidy were also studied. The results showed that the endopolyploidy levels were lower in lateral roots than in either primary or nodal roots. The lower endopolyploidy in lateral roots was attributed to cortical cells. P deficiency reduced the endopolyploidy levels in lateral roots and mature zone of primary roots. By contrast, salinity had no effects on the endopolyploidy levels in either lateral or primary roots, but had a minor effect on nodal roots. Transcript analysis of cell cycle-related genes showed that multiple cell cycle-related genes were more highly expressed in lateral roots than in primary roots, suggesting their roles in lowering endopolyploidy. P deficiency reduced HvCCS52A1 transcripts in the mature zone of primary roots, but had little effect on the transcripts of 12 cell cycle-related genes in lateral roots, suggesting that endopolyploidy regulation differs between lateral roots and primary roots. Our results revealed that endopolyploidy reduction in root systems could be an integrated part of endopolyploidy plasticity in barley growth and development as well as in adaptation to a low P environment.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2014
Publisher: Elsevier BV
Date: 11-1998
Publisher: IEEE
Date: 08-2011
Publisher: Wiley
Date: 11-01-2010
DOI: 10.1111/J.1365-3040.2009.02069.X
Abstract: Boron tolerance is a quantitative trait controlled by multiple genes. Suppression subtractive hybridization was carried out on root cDNA from bulked boron tolerant and intolerant doubled haploid barley lines grown under moderate boron stress to identify genes associated with boron tolerance. One hundred and eleven clones representing known proteins were found to be up-regulated in the tolerant bulk upon boron stress. Nine clones were genetically mapped to previously reported boron tolerance QTL. These include a clone identical to the boron transporter gene Bot1 and a clone coding for a bromo-adjacent homology domain-containing protein, mapping to the 6H boron tolerance locus and co-segregating with reduced boron intake in a Clipper x Sahara-3771 mapping population. A third clone mapping to the 2H QTL region encoding an S-adenosylmethionine decarboxylase precursor was found to provide tolerance to high boron by heterologous expression. Yeast cells expressing Sahara SAMDC were able to grow on 15 mm boron solid media and maintained cellular boron concentrations at 13% lower than control cells expressing empty vector. The data suggest that an antioxidative response mechanism involving polyamines and the ascorbate-glutathione pathway in Sahara barley may provide an advantage in tolerating high soil concentrations of boron.
Publisher: Springer Science and Business Media LLC
Date: 11-12-2010
Publisher: Springer Science and Business Media LLC
Date: 27-04-2017
Abstract: Barley ( Hordeum vulgare L.) is a cereal grass mainly used as animal fodder and raw material for the malting industry. The map-based reference genome sequence of barley cv. ‘Morex’ was constructed by the International Barley Genome Sequencing Consortium (IBSC) using hierarchical shotgun sequencing. Here, we report the experimental and computational procedures to (i) sequence and assemble more than 80,000 bacterial artificial chromosome (BAC) clones along the minimum tiling path of a genome-wide physical map, (ii) find and validate overlaps between adjacent BACs, (iii) construct 4,265 non-redundant sequence scaffolds representing clusters of overlapping BACs, and (iv) order and orient these BAC clusters along the seven barley chromosomes using positional information provided by dense genetic maps, an optical map and chromosome conformation capture sequencing (Hi-C). Integrative access to these sequence and mapping resources is provided by the barley genome explorer (BARLEX).
Publisher: Wiley
Date: 02-02-2005
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2014
Publisher: World Scientific
Date: 17-09-2018
DOI: 10.1142/11212
Publisher: Wiley
Date: 02-08-2018
DOI: 10.1111/PCE.13339
Abstract: Transcription factors regulate multiple networks, mediating the responses of organisms to stresses, including drought. Here, we investigated the role of the wheat transcription factor TaSHN1 in crop growth and drought tolerance. TaSHN1, isolated from bread wheat, was characterized for molecular interactions and functionality. The overexpression of TaSHN1 in wheat was followed by the evaluation of T
Publisher: Springer Netherlands
Date: 2013
Publisher: Springer Science and Business Media LLC
Date: 12-2013
Abstract: miR399 and miR827 are both involved in conserved phosphorus (P) deficiency signalling pathways. miR399 targets the PHO2 gene encoding E2 enzyme that negatively regulates phosphate uptake and root-to-shoot allocation, while miR827 targets SPX-domain-containing genes that negatively regulate other P-responsive genes. However, the response of miR399 and miR827 to P conditions in barley has not been investigated. In this study, we investigated the expression profiles of miR399 and miR827 in barley ( Hordeum vulagre L.) under P-deficient and P-sufficient conditions. We identified 10 members of the miR399 family and one miR827 gene in barley, all of which were significantly up-regulated under deficient P. In addition, we found many isomirs of the miR399 family and miR827, most of which were also significantly up-regulated under deficient P. Several isomirs of miR399 members were found to be able to cleave their predicted targets in vivo . Surprisingly, a few small RNAs (sRNAs) derived from the single-stranded loops of the hairpin structures of MIR399b and MIR399e-1 were also found to be able to cleave their predicted targets in vivo . Many antisense sRNAs of miR399 and a few for miR827 were also detected, but they did not seem to be regulated by P. Intriguingly, the lowest expressed member, hvu-miR399k, had four-fold more antisense sRNAs than sense sRNAs, and furthermore under P sufficiency, the antisense sRNAs are more frequent than the sense sRNAs. We identified a potential regulatory network among miR399, its target HvPHO2 and target mimics HvIPS1 and HvIPS2 in barley under P-deficient and P-sufficient conditions. Our data provide an important insight into the mechanistic regulation and function of miR399, miR827 and their isomirs in barley under different P conditions.
Publisher: OSA
Date: 2015
Publisher: Oxford University Press (OUP)
Date: 25-06-2010
Abstract: Boron (B) toxicity is a significant limitation to cereal crop production in a number of regions worldwide. Here we describe the cloning of a gene from barley (Hordeum vulgare), underlying the chromosome 6H B toxicity tolerance quantitative trait locus. It is the second B toxicity tolerance gene identified in barley. Previously, we identified the gene Bot1 that functions as an efflux transporter in B toxicity-tolerant barley to move B out of the plant. The gene identified in this work encodes HvNIP2 , an aquaporin from the nodulin-26-like intrinsic protein (NIP) subfamily that was recently described as a silicon influx transporter in barley and rice (Oryza sativa). Here we show that a rice mutant for this gene also shows reduced B accumulation in leaf blades compared to wild type and that the mutant protein alters growth of yeast (Saccharomyces cerevisiae) under high B. HvNIP2 facilitates significant transport of B when expressed in Xenopus oocytes compared to controls and to another NIP (NOD26), and also in yeast plasma membranes that appear to have relatively high B permeability. We propose that tolerance to high soil B is mediated by reduced expression of HvNIP2 to limit B uptake, as well as by increased expression of Bot1 to remove B from roots and sensitive tissues. Together with Bot1, the multifunctional aquaporin HvNIP2 is an important determinant of B toxicity tolerance in barley.
Publisher: Springer Science and Business Media LLC
Date: 1999
Publisher: Springer Science and Business Media LLC
Date: 24-06-2010
Publisher: Figshare
Date: 2017
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.COPBIO.2014.11.027
Abstract: Water deficit or drought stress is a major limitation to crop production globally. Plant breeders have used a wide range of technologies to successfully breed varieties that perform well under the growth conditions for their target environments but they are always seeking new opportunities to enhance rates of genetic gain. Under drought, yield is determined by the integration of variable levels of water deficit across the developmental life of the crop. Genomics technologies were seen as a path to understand the genetic and environmental complexity of drought stress. To be relevant to breeding programs, genomic studies must consider the nature of drought stress in the target environment and use plant material and phenotyping techniques that relate to field conditions.
Publisher: MDPI AG
Date: 10-11-2021
Abstract: Two genes, HvSAP8 and HvSAP16, encoding Zinc-finger proteins, were identified earlier as active in barley plants. Based on bioinformatics and sequencing analysis, six SNPs were found in the promoter regions of HvSAP8 and one in HvSAP16, among parents of two barley segregating populations, Granal × Baisheshek and Natali × Auksiniai-2. ASQ and Amplifluor markers were developed for HvSAP8 and HvSAP16, one SNP in each gene, and in each of two populations, showing simple Mendelian segregation. Plants of F6 selected breeding lines and parents were evaluated in a soil-based drought screen, revealing differential expression of HvSAP8 and HvSAP16 corresponding with the stress. After almost doubling expression during the early stages of stress, HvSAP8 returned to pre-stress level or was strongly down-regulated in plants with Granal or Baisheshek genotypes, respectively. For HvSAP16 under drought conditions, a high expression level was followed by either a return to original levels or strong down-regulation in plants with Natali or Auksiniai-2 genotypes, respectively. Grain yield in the same breeding lines and parents grown under moderate drought was strongly associated with their HvSAP8 and HvSAP16 genotypes. Additionally, Granal and Natali genotypes with specific alleles at HvSAP8 and HvSAP16 were associated with improved performance under drought via higher 1000 grain weight and more shoots per plant, respectively.
Publisher: Springer Science and Business Media LLC
Date: 28-09-2014
Publisher: Informa UK Limited
Date: 09-11-2013
DOI: 10.1080/19338244.2012.750588
Abstract: Coronary heart disease (CHD) is a major problem for firefighters, even when considering the healthy worker effect (HWE). Although volunteer firefighters outnumber paid personnel, previous research has focused on paid US firefighters. By contrast, no CHD data for Australian firefighters exist. Risk factor data were collected from 2,943 Australian volunteer firefighters and CHD risk was compared with reference "low-risk" and Australian population data. Predicted CHD risk for male and female firefighter was 19.2% and 5.1%, respectively. Female firefighters high blood pressure and fasting glucose was significantly lower than the general population, whereas all other risk factors was similar to the general population. Firefighters' CHD risk was greater than other volunteer and paid emergency services, but the prevalence for most risk factors was similar to the general population. Therefore, Australian volunteer firefighters may not benefit from the HWE.
Publisher: Springer-Verlag
Date: 2005
Publisher: Canadian Science Publishing
Date: 08-2003
DOI: 10.1139/G03-038
Abstract: Hypericum perforatum L. (St. John's wort) is widely used in homeopathic medicine, but has also become a serious weed in Australia and many other countries. Reproduction in H. perforatum was investigated using markers based on restriction fragment length polymorphism (RFLP) and lified fragment length polymorphism (AFLP). Between two Australian populations, plants displayed 14 polymorphisms from a total of 22 scorable RFLP markers when genomic DNA was probed with M13 bacteriophage, but in iduals within each population exhibited identical RFLP fingerprints. Ninety-four percent of the progeny of four crosses made between the two populations exhibited identical fingerprint and ploidy level to the maternal parent, and probably originated apomictically. Seven seedlings with recombinant RFLP or AFLP fingerprints were found from a total of 121 progeny. Both molecular marker techniques detected the same recombinants from a subset of screened progeny. Cytological analysis showed that the seven recombinants comprised three tetraploids (2n = 4x = 32), three hexaploids (2n = 6x = 48), and one aneuploid (2n 1 = 31), which suggested that the level of normal reduced embryo sacs was only 2.5%. These results are discussed in relation to the management of invasive populations, and the implications for plant breeding and production of St. John's wort for medicinal purposes. Key words: Hypericum perforatum, apomixis, DNA fingerprint, RFLP, AFLP.
Publisher: Oxford University Press (OUP)
Date: 10-2004
Abstract: The ancestral shared synteny concept has been advocated as an approach to positionally clone genes from complex genomes. However, the unified grass genome model and the study of grasses as a single syntenic genome is a topic of considerable controversy. Hence, more quantitative studies of cereal colinearity at the sequence level are required. This study compared a contiguous 300-kb sequence of the barley (Hordeum vulgare) genome with the colinear region in rice (Oryza sativa). The barley sequence harbors genes involved in endosperm texture, which may be the subject of distinctive evolutionary forces and is located at the extreme telomeric end of the short arm of chromosome 5H. Comparative sequence analysis revealed the presence of five orthologous genes and a complex, postspeciation evolutionary history involving small chromosomal rearrangements, a translocation, numerous gene duplications, and extensive transposon insertion. Discrepancies in gene content and microcolinearity indicate that caution should be exercised in the use of rice as a surrogate for map-based cloning of genes from large genome cereals such as barley.
Publisher: Springer Science and Business Media LLC
Date: 19-10-2014
Publisher: Laser Pages Publishing Ltd.
Date: 12-2007
Publisher: Elsevier BV
Date: 06-2006
DOI: 10.1016/J.TPLANTS.2006.04.004
Abstract: To date, alien introgression of agronomically important traits into bread wheat (Triticum aestivum) from wild relatives has not been readily achievable through traditional breeding practices. However, this door might now be unlocked. The insightful research published recently by Graham Moore and his team delivers a likely candidate in the form of a cdc2-kinase-related gene family for the Ph1 locus--a chromatin region located on chromosome 5B that is responsible for homologous chromosome pairing integrity in bread wheat.
Publisher: Springer Science and Business Media LLC
Date: 06-10-2016
Publisher: Wiley
Date: 05-1998
Publisher: Elsevier BV
Date: 12-2014
DOI: 10.1016/J.JTHERBIO.2014.10.003
Abstract: Monitoring an in idual's thermic state in the workplace requires reliable feedback of their core temperature. However, core temperature measurement technology is expensive, invasive and often impractical in operational environments, warranting investigation of surrogate measures which could be used to predict core temperature. This study examines an alternative measure of an in idual's thermic state, thermal sensation, which presents a more manageable and practical solution for Australian firefighters operating on the fireground. Across three environmental conditions (cold, warm, hot & humid), 49 Australian volunteer firefighters performed a 20-min fire suppression activity, immediately followed by 20 min of active cooling using hand and forearm immersion techniques. Core temperature (Tc) and thermal sensation (TS) were measured across the rehabilitation period at five minute intervals. Despite the decline in Tc and TS throughout the rehabilitation period, there was little similarity in the magnitude or rate of decline between each measure in any of the ambient conditions. Moderate to strong correlations existed between Tc and TS in the cool (0.41, p<0.05) and hot & humid (0.57, p<0.05) conditions, however this was resultant in strong correlation during the earlier stages of rehabilitation (first five minutes), which were not evident in the latter stages. Linear regression revealed TS to be a poor predictor of Tc in all conditions (SEE=0.45-0.54°C) with a strong trend for TS to over-predict Tc (77-80% of the time). There is minimal evidence to suggest that ratings of thermal sensation, which represent a psychophysical assessment of an in idual's thermal comfort, are an accurate reflection of the response of an in idual's core temperature. Ratings of thermal sensation can be highly variable amongst in iduals, likely moderated by local skin temperature. In account of these findings, fire managers require a more reliable source of information to guide decisions of heat stress management.
Publisher: Wiley
Date: 07-01-2018
DOI: 10.1111/TPJ.13794
Abstract: Pseudogenes have a reputation of being 'evolutionary relics' or 'junk DNA'. While they are well characterized in mammals, studies in more complex plant genomes have so far been h ered by the absence of reference genome sequences. Barley is one of the economically most important cereals and has a genome size of 5.1 Gb. With the first high-quality genome reference assembly available for a Triticeae crop, we conducted a whole-genome assessment of pseudogenes on the barley genome. We identified, characterized and classified 89 440 gene fragments and pseudogenes scattered along the chromosomes, with occasional hotspots and higher densities at the chromosome ends. Full-length pseudogenes (11 015) have preferentially retained their exon-intron structure. Retrotransposition of processed mRNAs only plays a marginal role in their creation. However, the distribution of retroposed pseudogenes reflects the Rabl configuration of barley chromosomes and thus hints at founding mechanisms. While parent genes related to the defense-response were found to be under-represented in cultivated barley, we detected several defense-related pseudogenes in wild barley accessions. The percentage of transcriptionally active pseudogenes is 7.2%, and these may potentially adopt new regulatory roles.The barley genome is rich in pseudogenes and small gene fragments mainly located towards chromosome tips or as tandemly repeated units. Our results indicate non-random duplication and pseudogenization preferences and improve our understanding of the dynamics of gene birth and death in large plant genomes and the mechanisms that lead to evolutionary innovations.
Publisher: SPIE
Date: 28-08-2008
DOI: 10.1117/12.793596
Publisher: Japanese Society of Breeding
Date: 2010
DOI: 10.1270/JSBBS.60.426
Publisher: Springer Science and Business Media LLC
Date: 25-02-2011
Abstract: MicroRNAs are important components of the regulatory network of biological systems and thousands have been discovered in both animals and plants. Systematic investigations performed in species with sequenced genomes such as Arabidopsis, rice, poplar and Brachypodium have provided insights into the evolutionary relationships of this class of small RNAs among plants. However, miRNAs from barley, one of the most important cereal crops, remain unknown. We performed a large scale study of barley miRNAs through deep sequencing of small RNAs extracted from leaves of two barley cultivars. By using the presence of miRNA precursor sequences in related genomes as one of a number of supporting criteria, we identified up to 100 miRNAs in barley. Of these only 56 have orthologs in wheat, rice or Brachypodium that are known to be expressed, while up to 44 appear to be specifically expressed in barley. Our study, the first large scale investigation of small RNAs in barley, has identified up to 100 miRNAs. We demonstrate that reliable identification of miRNAs via deep sequencing in a species whose genome has not been sequenced requires a more careful analysis of sequencing errors than is commonly performed. We devised a read filtering procedure for dealing with errors. In addition, we found that the use of a large dataset of almost 35 million reads permits the use of read abundance distributions along putative precursor sequences as a practical tool for isolating miRNAs in a large background of reads originating from other non-coding and coding RNAs. This study therefore provides a generic approach for discovering novel miRNAs where no genome sequence is available.
Publisher: Oxford University Press (OUP)
Date: 10-1999
Publisher: AIP Publishing
Date: 20-04-2020
DOI: 10.1063/5.0003589
Abstract: Photonic technology is widely based on anisotropic (and) nonlinear materials, which allow light modulation and parametric light conversion. Because the number of naturally occurring crystals is limited, there is a growing demand for artificial metamaterials with optical properties specifically tailored to a given application. Here, we utilize the top-down method to synthesize sub-wavelength periodic nanostructures inside a uniaxial optically nonlinear crystal (lithium niobate, LiNbO3) by irradiating it with multiple femtosecond laser pulses. By superimposing form-birefringence associated with the light-induced nanostructures onto natural birefringence of the host crystal we create macroscopic domains of a biaxial metamaterial embedded into otherwise uniaxial medium.
Publisher: Oxford University Press (OUP)
Date: 04-06-2010
DOI: 10.1093/JXB/ERQ152
Abstract: Tolerance to drought is a quantitative trait, with a complex phenotype, often confounded by plant phenology. Breeding for drought tolerance is further complicated since several types of abiotic stress, such as high temperatures, high irradiance, and nutrient toxicities or deficiencies can challenge crop plants simultaneously. Although marker-assisted selection is now widely deployed in wheat, it has not contributed significantly to cultivar improvement for adaptation to low-yielding environments and breeding has relied largely on direct phenotypic selection for improved performance in these difficult environments. The limited success of the physiological and molecular breeding approaches now suggests that a careful rethink is needed of our strategies in order to understand better and breed for drought tolerance. A research programme for increasing drought tolerance of wheat should tackle the problem in a multi-disciplinary approach, considering interaction between multiple stresses and plant phenology, and integrating the physiological dissection of drought-tolerance traits and the genetic and genomics tools, such as quantitative trait loci (QTL), microarrays, and transgenic crops. In this paper, recent advances in the genetics and genomics of drought tolerance in wheat and barley are reviewed and used as a base for revisiting approaches to analyse drought tolerance in wheat. A strategy is then described where a specific environment is targeted and appropriate germplasm adapted to the chosen environment is selected, based on extensive definition of the morpho-physiological and molecular mechanisms of tolerance of the parents. This information was used to create structured populations and develop models for QTL analysis and positional cloning.
Publisher: Springer Science and Business Media LLC
Date: 19-05-2011
Abstract: Although second generation sequencing (2GS) technologies allow re-sequencing of previously gold-standard-sequenced genomes, whole genome shotgun sequencing and de novo assembly of large and complex eukaryotic genomes is still difficult. Availability of a genome-wide physical map is therefore still a prerequisite for whole genome sequencing for genomes like barley. To start such an endeavor, large insert genomic libraries, i.e. Bacterial Artificial Chromosome (BAC) libraries, which are unbiased and representing deep haploid genome coverage, need to be ready in place. Five new BAC libraries were constructed for barley ( Hordeum vulgare L.) cultivar Morex. These libraries were constructed in different cloning sites ( Hind III, EcoR I, Mbo I and BstX I) of the respective vectors. In order to enhance unbiased genome representation and to minimize the number of gaps between BAC contigs, which are often due to uneven distribution of restriction sites, a mechanically sheared library was also generated. The new BAC libraries were fully characterized in depth by scrutinizing the major quality parameters such as average insert size, degree of contamination (plate wide, neighboring, and chloroplast), empty wells and off-scale clones (clones with or fragments). Additionally a set of gene-based probes were hybridized to high density BAC filters and showed that genome coverage of each library is between 2.4 and 6.6 X. BAC libraries representing haploid genomes are available as a new resource to the barley research community. Systematic utilization of these libraries in high-throughput BAC fingerprinting should allow developing a genome-wide physical map for the barley genome, which will be instrumental for map-based gene isolation and genome sequencing.
Publisher: Wiley
Date: 31-05-2010
Publisher: Oxford University Press (OUP)
Date: 22-09-2006
Abstract: Boron (B) is an essential micronutrient that affects plant growth at either deficient or toxic concentrations in soil. The aim of this work was to investigate the adaptation of barley (Hordeum vulgare) plants to toxic B levels and to increase our understanding of B toxicity tolerance mechanisms. We used a metabolomics approach to compare metabolite profiles in root and leaf tissues of an intolerant, commercial cultivar (cv Clipper) and a B-tolerant Algerian landrace (cv Sahara). After exposure to elevated B (200 and 1,000 μ m), the number and litude of metabolite changes in roots was greater in Clipper than in Sahara. In contrast, leaf metabolites of both cultivars only responded following 1,000 μ m treatment, at which B toxicity symptoms (necrosis) were visible. In addition, metabolite levels were dramatically altered in the tips of leaves of the sensitive cultivar Clipper after growth in 1,000 μ m B compared to those of Sahara. This correlates with a gradual accumulation of B from leaf base to tip in B-intolerant cultivars. Overall, there were always greater differences between tissue types (roots and leaves) than between the two cultivars. This work has provided insights into metabolic differences of two genetically distinct barley cultivars and information about how they respond metabolically to increasing B levels.
Publisher: Springer Science and Business Media LLC
Date: 30-10-2019
DOI: 10.1186/S12896-019-0565-Z
Abstract: The CRISPR-Cas9 system is a powerful and versatile tool for crop genome editing. However, achieving highly efficient and specific editing in polyploid species can be a challenge. The efficiency and specificity of the CRISPR-Cas9 system depends critically on the gRNA used. Here, we assessed the activities and specificities of seven gRNAs targeting 5-enolpyruvylshikimate-3-phosphate synthase ( EPSPS ) in hexaploid wheat protoplasts. EPSPS is the biological target of the widely used herbicide glyphosate. The seven gRNAs differed substantially in their on-target activities, with mean indel frequencies ranging from 0% to approximately 20%. There was no obvious correlation between experimentally determined and in silico predicted on-target gRNA activity. The presence of a single mismatch within the seed region of the guide sequence greatly reduced but did not abolish gRNA activity, whereas the presence of an additional mismatch, or the absence of a PAM, all but abolished gRNA activity. Large insertions (≥20 bp) of DNA vector-derived sequence were detected at frequencies up to 8.5% of total indels. One of the gRNAs exhibited several properties that make it potentially suitable for the development of non-transgenic glyphosate resistant wheat. We have established a rapid and reliable method for gRNA validation in hexaploid wheat protoplasts. The method can be used to identify gRNAs that have favourable properties. Our approach is particularly suited to polyploid species, but should be applicable to any plant species amenable to protoplast transformation.
Publisher: Wiley
Date: 20-12-2014
Publisher: Institute of Physical Optics
Date: 2011
Publisher: Oxford University Press (OUP)
Date: 03-2000
Publisher: The Optical Society
Date: 03-12-2008
DOI: 10.1364/OE.16.020902
Abstract: We generate experimentally optical bottle beams from incoherent double-charge white-light vortices, and show that their parameters can be efficiently controlled by varying the beam focusing conditions.
Publisher: Wiley
Date: 10-03-2015
DOI: 10.1111/PBI.12356
Publisher: Springer Science and Business Media LLC
Date: 04-2017
DOI: 10.1038/NATURE22043
Abstract: Cereal grasses of the Triticeae tribe have been the major food source in temperate regions since the dawn of agriculture. Their large genomes are characterized by a high content of repetitive elements and large pericentromeric regions that are virtually devoid of meiotic recombination. Here we present a high-quality reference genome assembly for barley (Hordeum vulgare L.). We use chromosome conformation capture mapping to derive the linear order of sequences across the pericentromeric space and to investigate the spatial organization of chromatin in the nucleus at megabase resolution. The composition of genes and repetitive elements differs between distal and proximal regions. Gene family analyses reveal lineage-specific duplications of genes involved in the transport of nutrients to developing seeds and the mobilization of carbohydrates in grains. We demonstrate the importance of the barley reference sequence for breeding by inspecting the genomic partitioning of sequence variation in modern elite germplasm, highlighting regions vulnerable to genetic erosion.
Publisher: OSA
Date: 2015
Publisher: Oxford University Press (OUP)
Date: 17-06-2021
DOI: 10.1093/JXB/ERAB256
Abstract: Despite being the world’s most widely grown crop, research investments in wheat (Triticum aestivum and Triticum durum) fall behind those in other staple crops. Current yield gains will not meet 2050 needs, and climate stresses compound this challenge. However, there is good evidence that heat and drought resilience can be boosted through translating promising ideas into novel breeding technologies using powerful new tools in genetics and remote sensing, for ex le. Such technologies can also be applied to identify climate resilience traits from among the vast and largely untapped reserve of wheat genetic resources in collections worldwide. This review describes multi-pronged research opportunities at the focus of the Heat and Drought Wheat Improvement Consortium (coordinated by CIMMYT), which together create a pipeline to boost heat and drought resilience, specifically: improving crop design targets using big data approaches developing phenomic tools for field-based screening and research applying genomic technologies to elucidate the bases of climate resilience traits and applying these outputs in developing next-generation breeding methods. The global impact of these outputs will be validated through the International Wheat Improvement Network, a global germplasm development and testing system that contributes key productivity traits to approximately half of the global wheat-growing area.
Publisher: Springer Science and Business Media LLC
Date: 08-08-2006
DOI: 10.1007/S00122-006-0370-7
Abstract: A doubled haploid population constructed from a cross between the South Australian wheat cultivars 'Trident' and 'Molineux' was grown under winter field conditions, under field conditions over summer and under artificial light both with and without vernalisation. The duration from planting to ear-emergence was recorded and QTL associated with heading date were detected using a previously constructed genetic linkage map. Associations were shown with chromosomal regions syntenous to previously identified photoperiod (Ppd-B1) and vernalisation (Vrn-A1) sensitive loci. Additional QTL associated with time to heading were also identified on chromosomes 1A, 2A, 2B, 6D, 7A and 7B. Comparisons between the genetic associations observed under the different growing conditions allowed the majority of these loci to be classified as having either photoperiod-sensitive, vernalisation-sensitive or earliness per se actions. The identification of a photoperiod-sensitive QTL on chromosome 1A provides evidence for a wheat gene possibly homoeologous to Ppd-H2 previously identified on chromosome 1H of barley. The occurrence of a putative major gene for photoperiod sensitivity observed on chromosome 7A is presented. The combined additive effects at these loci accounted for more than half the phenotypic variance in the duration from planting to ear-emergence in this population. The possible role of these loci on the adaptation of wheat in Australia is discussed.
Publisher: Oxford University Press (OUP)
Date: 2006
DOI: 10.1534/GENETICS.104.038489
Abstract: In human genetics a detailed knowledge of linkage disequilibrium (LD) is considered a prerequisite for effective population-based, high-resolution gene mapping and cloning. Similar opportunities exist for plants however, differences in breeding system and population history need to be considered. Here we report a detailed study of localized LD in different populations of an inbreeding crop species. We measured LD between and within four gene loci within the region surrounding the hardness locus in three different gene pools of barley (Hordeum vulgare). We demonstrate that LD extends to at least 212 kb in elite barley cultivars but is rapidly eroded in related inbreeding ancestral populations. Our results indicate that haplotype-based sequence analysis in multiple populations will provide new opportunities to adjust the resolution of association studies in inbreeding crop species.
Publisher: Springer Science and Business Media LLC
Date: 15-09-2016
Publisher: Oxford University Press (OUP)
Date: 03-02-2006
DOI: 10.1093/BFGP/ELI005
Abstract: Abiotic stresses such as extreme temperatures, low water availability, high salt and mineral deficiencies or toxicities severely diminish productivity of cereal crops. These stresses are becoming increasingly important because of the declining availability of good quality water, land degradation and community pressures to move away from chemical intervention in agriculture. Of the major cereals, wheat and barley are grown in the most hostile and consequently lowest yielding environments. Extensive genetic studies and surveys of landrace and wild germplasm have indicated extensive variation for abiotic stress tolerance but this has been difficult to exploit due to the relatively poor background knowledge of the molecular basis for stress in these species. Interconnected signal transduction pathways that lead to multiple responses to abiotic stresses have been difficult to study using traditional approaches because of their complexity and the large number of genes and gene products involved in the various defensive and developmental responses of the plant. Functional genomics is now widely seen as providing tools for dissecting abiotic stress responses in wheat and barley, through which networks of stress perception, signal transduction and defensive responses can be examined from gene transcription, through protein complements of cells, to the metabolite profiles of stressed tissues.
Publisher: Kluwer Academic Publishers
Date: 2005
Publisher: Elsevier BV
Date: 06-2012
Publisher: The Optical Society
Date: 18-08-2011
DOI: 10.1364/OE.19.017350
Publisher: Japanese Society of Breeding
Date: 2009
DOI: 10.1270/JSBBS.59.671
Publisher: Springer Science and Business Media LLC
Date: 26-06-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2018
Publisher: Wiley
Date: 02-1997
Publisher: Springer Science and Business Media LLC
Date: 15-06-2007
DOI: 10.1007/S00122-007-0579-0
Abstract: Toxicity due to high levels of soil boron (B) represents a significant limitation to cereal production in some regions, and the Bo1 gene provides a major source of B toxicity tolerance in bread wheat (Triticum aestivum L.). A novel approach was used to develop primers to lify and sequence gene fragments specifically from the Bo1 region of the hexaploid wheat genome. Single-nucleotide polymorphisms (SNPs) identified were then used to generate markers close to Bo1 on the distal end of chromosome 7BL. In the 16 gene fragments totaling 19.6 kb, SNPs were observed between the two cultivars Cranbrook and Halberd at a low frequency (one every 613 bp). Furthermore, SNPs were distributed unevenly, being limited to only two genes. In contrast, RFLP provided a much greater number of genetic markers, with every tested gene identifying polymorphism. Bo1 previously known only as a QTL was located as a discrete Mendelian locus. In total, 28 new RFLP, PCR and SSR markers were added to the existing map. The 1.8 cM Bo1 interval of wheat corresponds to a 227 kb section of rice chromosome 6L encoding 21 predicted proteins with no homology to any known B transporters. The co-dominant PCR marker AWW5L7 co-segregated with Bo1 and was highly predictive of B tolerance status within a set of 94 Australian bread wheat cultivars and breeding lines. The markers and rice colinearity described here represent tools that will assist B tolerance breeding and the positional cloning of Bo1.
Publisher: The Optical Society
Date: 25-10-2013
DOI: 10.1364/OE.21.026335
Publisher: Oxford University Press (OUP)
Date: 23-12-2013
Publisher: Elsevier BV
Date: 2002
Publisher: Figshare
Date: 2017
Publisher: Wiley
Date: 29-06-2015
DOI: 10.1111/PBI.12220
Publisher: Springer Science and Business Media LLC
Date: 21-11-2017
Publisher: Elsevier BV
Date: 2008
DOI: 10.1016/J.TIG.2007.11.001
Abstract: Elite cultivated crop gene pools of the Triticeae tribe (wheat, barley and rye) exhibit limited genetic ersity, raising concerns about our ability to increase or simply sustain crop yield and quality in the face of dynamic environmental and biotic threats. Although exploiting their wild relatives as a source of novel alleles is challenging, it has provided notable successes in cereal improvement for >100 years. Increasingly facile gene discovery, improved enabling technologies for genetics and breeding and a better understanding of the factors limiting practical exploitation of exotic germplasm promise to transform existing, and accelerate the development of new, strategies for efficient and directed germplasm utilization.
Publisher: Springer Science and Business Media LLC
Date: 06-1999
Publisher: Frontiers Media SA
Date: 18-11-2016
Publisher: Springer Science and Business Media LLC
Date: 10-06-2019
DOI: 10.1007/S11103-019-00889-9
Abstract: Several classes of transcription factors are involved in the activation of defensins. A new type of the transcription factor responsible for the regulation of wheat grain specific defensins was characterised in this work. HD-Zip class IV transcription factors constitute a family of multidomain proteins. A full-length cDNA of HD-Zip IV, designated TaGL7 was isolated from the developing grain of bread wheat, using a specific DNA sequence as bait in the Y1H screen. 3D models of TaGL7 HD complexed with DNA cis-elements rationalised differences that underlined accommodations of binding and non-binding DNA, while the START-like domain model predicted binding of lipidic molecules inside a concave hydrophobic cavity. The 3'-untranslated region of TaGL7 was used as a probe to isolate the genomic clone of TdGL7 from a BAC library prepared from durum wheat. The spatial and temporal activity of the TdGL7 promoter was tested in transgenic wheat, barley and rice. TdGL7 was expressed mostly in ovary at fertilisation and its promoter was active in a liquid endosperm during cellularisation and later in the endosperm transfer cells, aleurone, and starchy endosperm. The pattern of TdGL7 expression resembled that of genes that encode grain-specific lipid transfer proteins, particularly defensins. In addition, GL7 expression was upregulated by mechanical wounding, similarly to defensin genes. Co-bombardment of cultured wheat cells with TdGL7 driven by constitutive promoter and seven grain or root specific defensin promoters fused to GUS gene, revealed activation of four promoters. The data confirmed the previously proposed role of HD-Zip IV transcription factors in the regulation of genes that encode lipid transfer proteins involved in lipid transport and defence. The TdGL7 promoter could be used to engineer cereal grains with enhanced resistance to insects and fungal infections.
Publisher: MDPI AG
Date: 07-11-2022
Abstract: Wheat occupies a special role in global food security since, in addition to providing 20% of our carbohydrates and protein, almost 25% of the global production is traded internationally. The importance of wheat for food security was recognised by the Chief Agricultural Scientists of the G20 group of countries when they endorsed the establishment of the Wheat Initiative in 2011. The Wheat Initiative was tasked with supporting the wheat research community by facilitating collaboration, information and resource sharing and helping to build the capacity to address challenges facing production in an increasingly variable environment. Many countries invest in wheat research. Innovations in wheat breeding and agronomy have delivered enormous gains over the past few decades, with the average global yield increasing from just over 1 tonne per hectare in the early 1960s to around 3.5 tonnes in the past decade. These gains are threatened by climate change, the rapidly rising financial and environmental costs of fertilizer, and pesticides, combined with declines in water availability for irrigation in many regions. The international wheat research community has worked to identify major opportunities to help ensure that global wheat production can meet demand. The outcomes of these discussions are presented in this paper.
Publisher: Springer Science and Business Media LLC
Date: 07-2019
DOI: 10.1007/S11103-019-00893-Z
Abstract: Due to an unfortunate turn of events, the panels O to S are missing in Fig. 8 of the original publication. The correct Fig. 8 and its caption is published here and should be treated as definitive.
Publisher: Springer Science and Business Media LLC
Date: 22-08-2007
DOI: 10.1007/S00122-007-0628-8
Abstract: The grain yield of wheat is influenced by genotype, environment and genotype-by-environment interaction. A mapping population consisting of 182 doubled haploid progeny derived from a cross between the southern Australian varieties 'Trident' and 'Molineux', was used to characterise the interaction of previously mapped grain yield quantitative trait locus (QTL) with specific environmental covariables. Environments (17) used for grain yield assessment were characterised for latitude, rainfall, various temperature-based variables and stripe rust infection severity. The number of days in the growing season in which the maximum temperature exceeded 30 degrees C was identified as the variable with the largest effect on site mean grain yield. However, the greatest QTL-by-environmental covariable interactions were observed with the severity of stripe rust infection. The rust resistance allele at the Lr37/Sr38/Yr17 locus had the greatest positive effect on grain yield when an environment experienced a combination of high-stripe rust infection and cool days. The grain yield QTL, QGyld.agt-4D, showed a very similar QTL-by-environment covariable interaction pattern to the Lr37/Sr38/Yr17 locus, suggesting a possible role in rust resistance or tolerance. Another putative grain yield per se QTL, QGyld.agt-1B, displayed interactions with the quantity of winter and spring rainfall, the number of days in which the maximum temperature exceeded 30 degrees C, and the number of days with a minimum temperature below 10 degrees C. However, no cross-over interaction effect was observed for this locus, and the 'Molineux' allele remained associated with higher grain yield in response to all environmental covariables. The results presented here confirm that QGyld.agt-1B may be a prime candidate for marker-assisted selection for improved grain yield and wide adaptation in wheat. The benefit of analysing the interaction of QTL and environmental covariables, such as employed here, is discussed.
Publisher: SPIE
Date: 30-04-2010
DOI: 10.1117/12.854769
Publisher: Springer Science and Business Media LLC
Date: 12-2007
Abstract: Chromosome pairing, recombination and DNA repair are essential processes during meiosis in sexually reproducing organisms. Investigating the bread wheat ( Triticum aestivum L.) Ph2 ( P airing h omoeologous) locus has identified numerous candidate genes that may have a role in controlling such processes, including TaMSH7 , a plant specific member of the DNA mismatch repair family. Sequencing of the three MSH7 genes, located on the short arms of wheat chromosomes 3A, 3B and 3D, has revealed no significant sequence ergence at the amino acid level suggesting conservation of function across the homoeogroups. Functional analysis of MSH7 through the use of RNAi loss-of-function transgenics was undertaken in diploid barley ( Hordeum vulgare L.). Quantitative real-time PCR revealed several T 0 lines with reduced MSH7 expression. Positive segregants from two T 1 lines studied in detail showed reduced MSH7 expression when compared to transformed controls and null segregants. Expression of MSH6 , another member of the mismatch repair family which is most closely related to the MSH7 gene, was not significantly reduced in these lines. In both T 1 lines, reduced seed set in positive segregants was observed. Results presented here indicate, for the first time, a distinct functional role for MSH7 in vivo and show that expression of this gene is necessary for wild-type levels of fertility. These observations suggest that MSH7 has an important function during meiosis and as such remains a candidate for Ph2 .
Publisher: Oxford University Press (OUP)
Date: 09-2000
DOI: 10.1046/J.1365-2672.2000.01124.X
Abstract: Fourteen killer yeasts were assayed for their ability to kill species of yeast that are commonly associated with fermenting grape must and wine. A total of 147 of a possible 364 killer-sensitive interactions were observed at pH 4.5. Of the killer yeasts studied, Pichia anomala NCYC 434 displayed the broadest killing range. At a pH value comparable with those of wine ferments, pH 3.5, the incidence of killer-sensitive interactions was reduced by 700% across all the yeasts. Williopsis saturnus var. mrakii CBS 1707 exhibited the broadest killing range at the lower pH, killing more than half of the tester strains. Intraspecific variation in sensitivity to killer yeasts was observed in all species where more than one strain was tested. Also, in strains of Pichia anomala, Kluyveromyces lactis and Pichia membranifaciens, the three species in which more than one killer yeast was analysed, intraspecific variation in killer activity was observed.
Publisher: Oxford University Press (OUP)
Date: 13-07-2007
DOI: 10.1093/JXB/ERM142
Abstract: Zinc (Zn) deficiency reduces crop yields globally. This study investigated the importance of root morphological traits, especially root hairs, in plant growth and Zn uptake. Wild-type barley (Hordeum vulgare) Pallas and its root-hairless mutant brb were grown in soil and solution culture at different levels of Zn supply for 16 d. Root morphological traits (root length, diameter, and surface area) were measured using the WinRHIZOPro Image Analysis system. In soil culture, Pallas had greater shoot dry matter, shoot Zn concentration, shoot Zn content, and Zn uptake per cm(2) root surface area than brb, primarily under zinc deficiency. Both Pallas and brb developed longer roots under Zn deficiency. Development of root hairs was not affected by plant Zn status. In solution culture, there were no significant genotypic differences in any of the parameters measured, indicating that mutation in brb does not affect growth and Zn uptake. However, both Pallas and brb developed longer and thinner roots, and root hair growth was less than in soil culture, and was not affected by plant Zn status. The better growth and greater Zn uptake of Pallas compared with brb in Zn-deficient soil can be attributed primarily to greater root surface area due to root hairs in Pallas rather than other root morphological differences.
Publisher: Public Library of Science (PLoS)
Date: 20-03-2015
Publisher: Wiley
Date: 21-04-2011
DOI: 10.1111/J.1469-8137.2011.03733.X
Abstract: Plant development is adapted to changing environmental conditions for optimizing growth. This developmental adaptation is influenced by signals from the environment, which act as stimuli and may include submergence and fluctuations in water status, light conditions, nutrient status, temperature and the concentrations of toxic compounds. The homeodomain‐leucine zipper (HD‐Zip) I and HD‐Zip II transcription factor networks regulate these plant growth adaptation responses through integration of developmental and environmental cues. Evidence is emerging that these transcription factors are integrated with phytohormone‐regulated developmental networks, enabling environmental stimuli to influence the genetically preprogrammed developmental progression. Dependent on the prevailing conditions, adaptation of mature and nascent organs is controlled by HD‐Zip I and HD‐Zip II transcription factors through suppression or promotion of cell multiplication, differentiation and expansion to regulate targeted growth. In vitro assays have shown that, within family I or family II, homo‐ and/or heterodimerization between leucine zipper domains is a prerequisite for DNA binding. Further, both families bind similar 9‐bp pseudopalindromic cis elements, CAATNATTG, under in vitro conditions. However, the mechanisms that regulate the transcriptional activity of HD‐Zip I and HD‐Zip II transcription factors in vivo are largely unknown. The in planta implications of these protein–protein associations and the similarities in cis element binding are not clear. Contents Summary 823 I. Introduction 824 II. The role of HD‐Zip transcription factors in plant growth adaptation to environmental changes and the phytohormone network 825 III. Dissecting the common cis element, dimerization and cell specificity of HD‐Zip I and HD‐Zip II transcription factors 830 IV. Conclusions 834 Acknowledgements 834 References 834
Publisher: Springer Science and Business Media LLC
Date: 18-03-2006
DOI: 10.1007/S10142-006-0025-4
Abstract: Assaying relative and absolute levels of gene expression in a erse series of tissues is a central step in the process of characterizing gene function and a necessary component of almost all publications describing in idual genes or gene family members. However, throughout the literature, such studies lack consistency in genotype, tissues analyzed, and growth conditions applied, and, as a result, the body of information that is currently assembled is fragmented and difficult to compare between different studies. The development of a comprehensive platform for assaying gene expression that is available to the entire research community provides a major opportunity to assess whole biological systems in a single experiment. It also integrates detailed knowledge and information on in idual genes into a unified framework that provides both context and resource to explore their contributions in a broader biological system. We have established a data set that describes the expression of 21,439 barley genes in 15 tissues s led throughout the development of the barley cv. Morex grown under highly controlled conditions. Rather than attempting to address a specific biological question, our experiment was designed to provide a reference gene expression data set for barley researchers a gene expression atlas and a comparative data set for those investigating genes or regulatory networks in other plant species. In this paper we describe the tissues s led and their transcriptomes, and provide summary information on genes that are either specifically expressed in certain tissues or show correlated expression patterns across all 15 tissue s les. Using specific ex les and an online tutorial, we describe how the data set can be interrogated for patterns and levels of barley gene expression and how the resulting information can be used to generate and/or test specific biological hypotheses.
Publisher: Oxford University Press (OUP)
Date: 31-10-2013
DOI: 10.1093/JXB/ERT333
Abstract: Global food security demands the development and delivery of new technologies to increase and secure cereal production on finite arable land without increasing water and fertilizer use. There are several options for boosting wheat yields, but most offer only small yield increases. Wheat is an inbred plant, and hybrids hold the potential to deliver a major lift in yield and will open a wide range of new breeding opportunities. A series of technological advances are needed as a base for hybrid wheat programmes. These start with major changes in floral development and architecture to separate the sexes and force outcrossing. Male sterility provides the best method to block self-fertilization, and modifying the flower structure will enhance pollen access. The recent explosion in genomic resources and technologies provides new opportunities to overcome these limitations. This review outlines the problems with existing hybrid wheat breeding systems and explores molecular-based technologies that could improve the hybrid production system to reduce hybrid seed production costs, a prerequisite for a commercial hybrid wheat system.
Publisher: Elsevier BV
Date: 07-2015
Publisher: Public Library of Science (PLoS)
Date: 20-07-2016
Publisher: The Optical Society
Date: 13-01-2012
DOI: 10.1364/OL.37.000226
Publisher: Springer Science and Business Media LLC
Date: 14-03-2021
Publisher: IEEE
Date: 09-2010
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2015
Publisher: Wiley
Date: 03-09-2013
DOI: 10.1111/NPH.12468
Abstract: High expression of zinc ( Z n)‐regulated, iron‐regulated transporter‐like protein ( ZIP ) genes increases root Z n uptake in dicots, leading to high accumulation of Z n in shoots. However, none of the ZIP genes tested previously in monocots could enhance shoot Z n accumulation. In this report, barley ( H ordeum vulgare ) H v ZIP 7 was investigated for its functions in Z n transport. The functions of H v ZIP 7 in planta were studied using in situ hybridization and transient analysis of subcellular localization with a green fluorescent protein ( GFP ) reporter. Transgenic barley lines overexpressing H v ZIP 7 were also generated to further understand the functions of H v ZIP 7 in metal transport. H v ZIP 7 is strongly induced by Z n deficiency, primarily in vascular tissues of roots and leaves, and its protein was localized in the plasma membrane. These properties are similar to its closely related homologs in dicots. Overexpression of H v ZIP 7 in barley plants increased Z n uptake when moderately high concentrations of Z n were supplied. Significantly, there was a specific enhancement of shoot Z n accumulation, with no measurable increase in iron ( F e), manganese ( M n), copper ( C u) or cadmium ( C d). H v ZIP 7 displays characteristics of low‐affinity Z n transport. The unique function of H v ZIP 7 provides new insights into the role of ZIP genes in Z n homeostasis in monocots, and offers opportunities to develop Z n biofortification strategies in cereals.
Publisher: Frontiers Media SA
Date: 17-11-2017
Publisher: Proceedings of the National Academy of Sciences
Date: 28-05-2019
Publisher: Public Library of Science (PLoS)
Date: 26-07-2016
Publisher: Springer Science and Business Media LLC
Date: 07-1998
Publisher: Elsevier BV
Date: 2005
Publisher: Springer Science and Business Media LLC
Date: 02-07-2014
DOI: 10.1038/NATURE13538
Abstract: Environmental constraints severely restrict crop yields in most production environments, and expanding the use of variation will underpin future progress in breeding. In semi-arid environments boron toxicity constrains productivity, and genetic improvement is the only effective strategy for addressing the problem. Wheat breeders have sought and used available genetic ersity from landraces to maintain yield in these environments however, the identity of the genes at the major tolerance loci was unknown. Here we describe the identification of near-identical, root-specific boron transporter genes underlying the two major-effect quantitative trait loci for boron tolerance in wheat, Bo1 and Bo4 (ref. 2). We show that tolerance to a high concentration of boron is associated with multiple genomic changes including tetraploid introgression, dispersed gene duplication, and variation in gene structure and transcript level. An allelic series was identified from a panel of bread and durum wheat cultivars and landraces originating from erse agronomic zones. Our results demonstrate that, during selection, breeders have matched functionally different boron tolerance alleles to specific environments. The characterization of boron tolerance in wheat illustrates the power of the new wheat genomic resources to define key adaptive processes that have underpinned crop improvement.
Publisher: Frontiers Media SA
Date: 26-04-2019
Publisher: Frontiers Media SA
Date: 07-02-2019
Publisher: Elsevier BV
Date: 08-2001
Publisher: Wiley
Date: 03-2011
DOI: 10.1038/OBY.2010.312
Abstract: Existing work demonstrates that obesity is independently associated with cognitive dysfunction and macrostructural brain changes however, little is known about the association between obesity and white matter (WM) integrity. We explore this relationship in a large cohort of otherwise healthy subjects. The present study classified 103 adult participants from the Brain Resource International Database between 21 and 86 years of age without history of neurological, medical, or psychiatric illness according to BMI (normal weight, overweight, obese) and subjected them to diffusion tensor imaging (DTI). Resulting fractional anisotropy (FA) indexes for the corpus callosum and fornix were examined in relation to BMI and age in a multiple regression framework. Results indicated that increasing BMI was independently associated with lower FA in the genu, splenium, and fornix, and a BMI × age interaction emerged for FA in the splenium and body of the corpus callosum. When categorized, obese persons demonstrated lower FA than normal and overweight persons for all WM indexes, but no FA differences emerged between overweight and normal persons. Results indicate both a direct association between obesity and reduced WM tract integrity and an interaction between obesity and aging processes on certain WM tracts in otherwise healthy adults. While such findings suggest a possible role for adiposity in WM dysfunction and associated cognitive deficits, prospective studies are needed to clarify the nature of these relationships and elucidate underlying mechanisms.
Publisher: Figshare
Date: 2011
Publisher: American Chemical Society (ACS)
Date: 07-10-2000
DOI: 10.1021/BI000688S
Abstract: Barley beta-amylase undergoes proteolytic cleavage in the C-terminal region after germination. The implication of the cleavage in the enzyme's characteristics is unclear. With purified native beta-amylases from both mature barley grain and germinated barley, we found that the beta-amylase from germinated barley had significantly higher thermostability and substrate binding affinity for starch than that from mature barley grain. To better understand the effect of the proteolytic cleavage on the enzyme's thermostability and substrate binding affinity for starch, recombinant barley beta-amylases with specific deletions at the C-terminal tail were generated. The complete deletion of the four C-terminal glycine-rich repeats significantly increased the enzyme's thermostability, but an incomplete deletion with one repeat remaining did not change the thermostability. Although different C-terminal deletions affect the thermostability differently, they all increased the enzyme's affinity for starch. The possible reasons for the increased thermostability and substrate binding affinity, due to the removal of the four C-terminal glycine-rich repeats, are discussed in terms of the three-dimensional structure of beta-amylase.
Publisher: CSIRO Publishing
Date: 2006
DOI: 10.1071/AR05384
Abstract: To enhance genetic maps of barley previously developed in Australia for identifying markers useable in molecular breeding, a new set of simple sequence repeat (SSR) and indel markers was added to the maps. These markers were developed through (i) database mining of barley expressed sequence tag (EST) sequences, (ii) comparative barley-rice genome analysis, and (iii) screening of a genomic library with SSR probes. The primer set selected for this study comprised 216 EST-SSR (eSSR) and 25 genomic SSR (gSSR) markers, which were screened for polymorphism on 4 doubled haploid (DH) or recombinant inbred line (RIL) populations. In total, 81 new markers were added to the maps, with good coverage on all 7 chromosomes, except 6H, which only had 2 new markers added. The marker order of previously published maps was re-evaluated by comparing recombination fractions calculated by 2 methods to discover the best position for each marker. The new SSR markers were then added to the updated maps. Several of these new markers are linked to important barley disease resistance genes such as those for cereal cyst nematode, spot form of net blotch, and leaf scald resistance, and are readily useable for marker-assisted barley breeding. The new maps are available on-line at www.genica.net.au.
Publisher: Springer Science and Business Media LLC
Date: 27-05-2021
Publisher: The Optical Society
Date: 03-12-2012
Publisher: MDPI AG
Date: 08-09-2020
Abstract: We investigated the roles of two Ferrochelatases (FCs), which encode the terminal enzyme for heme biosynthesis, in drought and oxidative stress tolerance in model cereal plant barley (Hordeum vulgare). Three independent transgenic lines ectopically overexpressing either barley FC1 or FC2 were selected and evaluated under well-watered, drought, and oxidative stress conditions. Both HvFC1 and HvFC2 overexpressing transgenics showed delayed wilting and maintained higher photosynthetic performance relative to controls, after exposure to soil dehydration. In each case, HvFC overexpression significantly upregulated the nuclear genes associated with detoxification of reactive oxygen species (ROS) upon drought stress. Overexpression of HvFCs, also suppressed photo-oxidative damage induced by the deregulated tetrapyrrole biosynthesis mutant tigrinad12. Previous studies suggest that only FC1 is implicated in stress defense responses, however, our study demonstrated that both FC1 and FC2 affect drought stress tolerance. As FC-derived free heme was proposed as a chloroplast-to-nuclear signal, heme could act as an important signal, stimulating drought responsive nuclear gene expression. This study also highlighted tetrapyrrole biosynthetic enzymes as potential targets for engineering improved crop performance, both in well-watered and water-limited environments.
Publisher: Elsevier BV
Date: 06-2016
DOI: 10.1016/J.PBI.2016.04.005
Abstract: Physiological breeding crosses parents with different complex but complementary traits to achieve cumulative gene action for yield, while selecting progeny using remote sensing, possibly in combination with genomic selection. Physiological approaches have already demonstrated significant genetic gains in Australia and several developing countries of the International Wheat Improvement Network. The techniques involved (see Graphical Abstract) also provide platforms for research and refinement of breeding methodologies. Recent ex les of these include screening genetic resources for novel expression of Calvin cycle enzymes, identification of common genetic bases for heat and drought adaptation, and genetic dissection of trade-offs among yield components. Such information, combined with results from physiological crosses designed to test novel trait combinations, lead to more precise breeding strategies, and feed models of genotype-by-environment interaction to help build new plant types and experimental environments for future climates.
Publisher: Elsevier BV
Date: 05-2013
Publisher: IEEE
Date: 05-2011
Publisher: Oxford University Press (OUP)
Date: 12-2014
Publisher: Oxford University Press (OUP)
Date: 15-11-2013
Abstract: Barley (Hordeum vulgare) is an important cereal crop and a model species for Triticeae genomics. To lay the foundation for hierarchical map-based sequencing, a genome-wide physical map of its large and complex 5.1 billion-bp genome was constructed by high-information content fingerprinting of almost 600,000 bacterial artificial chromosomes representing 14-fold haploid genome coverage. The resultant physical map comprises 9,265 contigs with a cumulative size of 4.9 Gb representing 96% of the physical length of the barley genome. The reliability of the map was verified through extensive genetic marker information and the analysis of topological networks of clone overlaps. A minimum tiling path of 66,772 minimally overlapping clones was defined that will serve as a template for hierarchical clone-by-clone map-based shotgun sequencing. We integrated whole-genome shotgun sequence data from the in iduals of two mapping populations with published bacterial artificial chromosome survey sequence information to genetically anchor the physical map. This novel approach in combination with the comprehensive whole-genome shotgun sequence data sets allowed us to independently validate and improve a previously reported physical and genetic framework. The resources developed in this study will underpin fine-mapping and cloning of agronomically important genes and the assembly of a draft genome sequence.
Publisher: Wiley
Date: 05-2019
Publisher: AIP
Date: 2010
DOI: 10.1063/1.3507112
Publisher: The Optical Society
Date: 30-04-2022
DOI: 10.1364/OE.17.008201
Abstract: We develop a theoretical approach for describing the optical trapping and manipulation of carbon nanoclusters in air with a dual-vortex optical trap, as realized recently in experiment [V. Shvedov et al., Opt. Express 17, 5743 (2009)]. We calculate both longitudinal and transverse photophoretic forces acting on a spherical absorbing particle, and then compare our theoretical predictions with the experimental data.
Publisher: Canadian Science Publishing
Date: 10-2004
DOI: 10.1139/G04-017
Abstract: Self incompatibility (SI) in Phalaris coerulescens is gametophytically determined by two unlinked multi allelic loci (S and Z). Neither the S nor Z genes have yet been cloned. As part of a map-based cloning strategy, high-resolution maps of the S and Z regions were generated from distorted segregating populations using RFLP probes from wheat, barley, oat, and Phalaris. The S locus was delimited to 0.26 cM with two boundary markers (Xwg811 and Xpsr168) and cosegregated with Xbm2 and Xbcd762. Xbcd266 was the closest marker linked to Z (0.9 cM). A high level of colinearity in the S and Z regions was found in both self-incompatible and -compatible species. The S locus was localized to the subcentromere region of chromosome 1 and the Z locus to the long arm end of chromosome 2. Several rice BAC clones orthologous to the S and Z locus regions were identified. This opens the possibility of using the rice genome sequence data to generate more closely linked markers and identify SI candidate genes. These results add further support to the conservation of gene order in the S and Z regions of the grass genomes.Key words: Phalaris coerulescens, self-incompatibility, distorted segregation, mapping, map-based cloning, synteny mapping.
Publisher: Springer Science and Business Media LLC
Date: 21-01-2019
Publisher: Springer Science and Business Media LLC
Date: 08-03-2007
DOI: 10.1007/S00122-007-0503-7
Abstract: A microsatellite or simple sequence repeat (SSR) consensus map of barley was constructed by joining six independent genetic maps based on the mapping populations 'Igri x Franka', 'Steptoe x Morex', 'OWB(Rec) x OWB(Dom)', 'Lina x Canada Park', 'L94 x Vada' and 'SusPtrit x Vada'. Segregation data for microsatellite markers from different research groups including SCRI (Bmac, Bmag, EBmac, EBmag, HVGeneName, scsssr), IPK (GBM, GBMS), WUR (GBM), Virginia Polytechnic Institute (HVM), and MPI for Plant Breeding (HVGeneName), generated in above mapping populations, were used in the computer program RECORD to order the markers of the in idual linkage data sets. Subsequently, a framework map was constructed for each chromosome by integrating the 496 "bridge markers" common to two or more in idual maps with the help of the computer programme JoinMap 3.0. The final map was calculated by following a "neighbours" map approach. The integrated map contained 775 unique microsatellite loci, from 688 primer pairs, ranging from 93 (6H) to 132 (2H) and with an average of 111 markers per linkage group. The genomic DNA-derived SSR marker loci had a higher polymorphism information content value (average 0.61) as compared to the EST/gene-derived SSR loci (average 0.48). The consensus map spans 1,068 cM providing an average density of one SSR marker every 1.38 cM. Such a high-density consensus SSR map provides barley molecular breeding programmes with a better choice regarding the quality of markers and a higher probability of polymorphic markers in an important chromosomal interval. This map also offers the possibilities of thorough alignment for the (future) physical map and implementation in haplotype ersity studies of barley.
Publisher: Oxford University Press (OUP)
Date: 09-2000
DOI: 10.1104/PP.124.1.415
Abstract: Phosphate (P) is taken up by plants through high-affinity P transporter proteins embedded in the plasma membrane of certain cell types in plant roots. Expression of the genes that encode these transporters responds to the P status of the plants, and their transcription is normally tightly controlled. However, this tight control of P uptake is lost under Zn deficiency, leading to very high accumulation of P in plants. We examined the effect of plant Zn status on the expression of the genes encoding the HVPT1 and HVPT2 high-affinity P transporters in barley (Hordeum vulgareL. cv Weeah) roots. The results show that the expression of these genes is intimately linked to the Zn status of the plants. Zn deficiency induced the expression of genes encoding these P transporters in plants grown in either P-sufficient or -deficient conditions. Moreover, the role of Zn in the regulation of these genes is specific in that it cannot be replaced by manganese (a alent cation similar to Zn). It appears that Zn plays a specific role in the signal transduction pathway responsible for the regulation of genes encoding high-affinity P transporters in plant roots. The significance of Zn involvement in the regulation of genes involved in P uptake is discussed.
Publisher: The Optical Society
Date: 02-2010
DOI: 10.1364/OE.18.003258
Publisher: The Optical Society
Date: 28-01-2010
DOI: 10.1364/OE.18.003137
Publisher: Springer Science and Business Media LLC
Date: 14-03-2007
DOI: 10.1007/S10142-006-0026-3
Abstract: A multigene family expressed during early floral development was identified on the short arm of wheat chromosome 3D in the region of the Ph2 locus, a locus controlling homoeologous chromosome pairing in allohexaploid wheat. Physical, genetic and molecular characterisation of the Wheat Meiosis 1 (WM1) gene family identified seven members that localised within a region of 173-kb. WM1 gene family members were sequenced and they encode mainly type Ia plasma membrane-anchored leucine rich repeat-like receptor proteins. In situ expression profiling suggests the gene family is predominantly expressed in floral tissue. In addition to the WM1 gene family, a number of other genes, gene fragments and pseudogenes were identified. It has been predicted that there is approximately one gene every 19-kb and that this region of the wheat genome contains 23 repetitive elements including BARE-1 and Wis2-1 like sequences. Nearly 50% of the repetitive elements identified were similar to known transposons from the CACTA superfamily. Ty1-copia, Ty3-gypsy and Athila LTR retroelements were also prevalent within the region. The WM1 gene cluster is present on 3DS and on barley 3HS but missing from the A and B genomes of hexaploid wheat. This suggests either recent generation of the cluster or specific deletion of the cluster during wheat polyploidisation. The evolutionary significance of the cluster, its possible roles in disease response or floral and early meiotic development and its location at or near the Ph2 locus are discussed.
Publisher: Oxford University Press (OUP)
Date: 2009
Publisher: The Optical Society
Date: 05-2015
DOI: 10.1364/OE.23.012444
Publisher: The Optical Society
Date: 14-05-2201
DOI: 10.1364/OL.35.001692
Publisher: Frontiers Media SA
Date: 07-09-2017
Publisher: Oxford University Press (OUP)
Date: 27-07-2015
DOI: 10.1093/JXB/ERV370
Publisher: The Optical Society
Date: 30-07-2028
DOI: 10.1364/OL.35.002660
Publisher: American Association for the Advancement of Science (AAAS)
Date: 12-02-2010
Abstract: To feed the several billion people living on this planet, the production of high-quality food must increase with reduced inputs, but this accomplishment will be particularly challenging in the face of global environmental change. Plant breeders need to focus on traits with the greatest potential to increase yield. Hence, new technologies must be developed to accelerate breeding through improving genotyping and phenotyping methods and by increasing the available genetic ersity in breeding germplasm. The most gain will come from delivering these technologies in developing countries, but the technologies will have to be economically accessible and readily disseminated. Crop improvement through breeding brings immense value relative to investment and offers an effective approach to improving food security.
Publisher: Wiley
Date: 06-09-2004
Publisher: Springer Science and Business Media LLC
Date: 24-02-2015
Publisher: Frontiers Media SA
Date: 27-09-2018
Publisher: Springer Berlin Heidelberg
Date: 2008
Publisher: IOP Publishing
Date: 15-07-2105
Publisher: Wiley
Date: 05-05-2016
DOI: 10.1111/PBI.12385
Abstract: Drought tolerance of the wheat cultivar Bobwhite was previously enhanced by transformation with a construct containing the wheat DREB3 gene driven by the stress-inducible maize Rab17 promoter. Progeny of a single T2 transgenic line were used as pollinators in crosses with four elite bread wheat cultivars from Western Australia: Bonnie Rock, IGW-2971, Magenta and Wyalkatchem, with the aim of evaluating transgene performance in different genetic backgrounds. The selected pollinator line, BW8-9-10-3, contained multiple transgene copies, had significantly improved drought tolerance compared with wild-type plants and showed no growth and development penalties or abnormalities. A single hybrid plant was selected from each cross-combination for three rounds of backcrossing with the corresponding maternal wheat cultivar. The transgene was detected in all four F1 BC3 combinations, but stress-inducible transgene expression was found in only three of the four combinations. Under well-watered conditions, the phenotypes and grain yield components of the F2 BC3 transgene-expressing lines were similar to those of corresponding recurrent parents and null-segregants. Under severe drought conditions, the backcross lines demonstrated 12-18% higher survival rates than the corresponding control plants. Two from four F3 BC3 transgenic lines showed significantly higher yield (18.9% and 21.5%) than control plants under limited water conditions. There was no induction of transgene expression under cold stress, and therefore, no improvement of frost tolerance observed in the progenies of drought-tolerant F3 BC3 lines.
Publisher: SPIE
Date: 08-10-2009
DOI: 10.1117/12.849660
Publisher: Wiley
Date: 2002
DOI: 10.1002/YEA.834
Abstract: Glycerol is a major fermentation product of Saccharomyces cerevisiae that contributes to the sensory character of wine. Diverting sugar to glycerol overproduction and away from ethanol production by overexpressing the glycerol 3-phosphate dehydrogenase gene,GPD2, caused S. cerevisiae to produce more than twice as much acetic acid as the wild-type strain (S288C background) in anaerobic cell culture. Deletion of the aldehyde dehydrogenase gene, ALD6, in wild-type and GPD2 overexpressing strains (GPD2-OP) decreased acetic acid production by three- and four-fold, respectively. In conjunction with reduced acetic acid production, the GPD2-OP ald6Delta strain produced more glycerol and less ethanol than the wild-type. The growth rate and fermentation rate were similar for the modified and wild-type strains, although the fermentation rate for the GPD2 ald6Delta strain was slightly less than that of the other strains from 24h onwards. Analysis of the metabolome of the mutants revealed that genetic modification affected the production of some secondary metabolites of fermentation, including acids, esters, aldehydes and higher alcohols, many of which are flavour-active in wine. Modification of GPD2 and ALD6 expression represents an effective strategy to increase the glycerol and decrease the ethanol concentration during fermentation, and alters the chemical composition of the medium such that, potentially, novel flavour ersity is possible. The implications for the use of these modifications in commercial wine production require further investigation in wine yeast strains.
Publisher: The Optical Society
Date: 16-05-2013
DOI: 10.1364/OE.21.012651
Publisher: MDPI AG
Date: 11-09-2020
Abstract: Ferrochelatase (FC) is the terminal enzyme of heme biosynthesis. In photosynthetic organisms studied so far, there is evidence for two FC isoforms, which are encoded by two genes (FC1 and FC2). Previous studies suggest that these two genes are required for the production of two physiologically distinct heme pools with only FC2-derived heme involved in photosynthesis. We characterised two FCs in barley (Hordeum vulgare L.). The two HvFC isoforms share a common catalytic domain, but HvFC2 additionally contains a C-terminal chlorophyll a/b binding (CAB) domain. Both HvFCs are highly expressed in photosynthetic tissues, with HvFC1 transcripts also being abundant in non-photosynthetic tissues. To determine whether these isoforms differentially affect photosynthesis, transgenic barley ectopically overexpressing HvFC1 and HvFC2 were generated and evaluated for photosynthetic performance. In each case, transgenics exhibited improved photosynthetic rate (Asat), stomatal conductance (gs) and carboxylation efficiency (CE), showing that both FC1 and FC2 play important roles in photosynthesis. Our finding that modified FC expression can improve photosynthesis up to ~13% under controlled growth conditions now requires further research to determine if this can be translated to improved yield performance under field conditions.
Publisher: Wiley
Date: 17-10-2003
DOI: 10.1046/J.1365-313X.2003.01891.X
Abstract: Colinearity in gene content and order between rice and closely related grass species has emerged as a powerful tool for gene identification. Using a comparative genetics approach, we have identified the rice genomic region syntenous to the region deleted in the wheat chromosome pairing mutant ph2a, with a view to identifying genes at the Ph2 locus that control meiotic processes. Utilising markers known to reside within the region deleted in ph2a, and data from wheat, barley and rice genetic maps, markers delimiting the region deleted on wheat chromosome 3DS in the ph2a mutant were used to locate the syntenous region on the short arm of rice chromosome 1. A contig of rice genomic sequence was identified from publicly available sequence information and used in blast searches to identify wheat expressed sequence tags (ESTs) exhibiting significant similarity. Southern analysis using a subset of identified wheat ESTs confirmed a syntenous relationship between the rice and wheat genomic regions and defined precisely the extent of the deleted segment in the ph2a mutant. A 6.58-Mb rice contig generated from 60 overlapping rice chromosome 1 P1 artificial chromosome (PAC) clones spanning the syntenous rice region has enabled identification of 218 wheat ESTs putatively located in the region deleted in ph2a. What seems to be a terminal deletion on chromosome 3DS is estimated to be 80 Mb in length. Putative candidate genes that may contribute to the altered meiotic phenotype of ph2a are discussed.
Publisher: Hindawi Limited
Date: 10-2003
Publisher: The Optical Society
Date: 24-03-2009
DOI: 10.1364/OL.34.001021
Abstract: We study theoretically and verify experimentally the detailed dynamics of spin-to-orbital angular momentum conversion for a circularly polarized Gaussian beam propagating along the optical axis of a uniaxial crystal. We extend the results to the case of white-light beams when each of the spectral components undergoes its own wavelength-dependent angular momentum conversion process.
Publisher: Springer Science and Business Media LLC
Date: 08-05-2017
Publisher: American Physical Society (APS)
Date: 10-09-2010
Publisher: Springer International Publishing
Date: 2018
Publisher: Wiley
Date: 04-08-2017
DOI: 10.1111/PCE.12764
Abstract: Drought is a crucial environmental constraint limiting crop production in many parts of the world. microRNA (miRNA) based gene regulation has been shown to act in several pathways, including crop response to drought stress. Sequence based profiling and computational analysis have revealed hundreds of miRNAs and their potential targets in different plant species under various stress conditions, but few have been biologically verified. In this study, 11 candidate miRNAs were tested for their expression profiles in barley. Differences in accumulation of only four miRNAs (Ath-miR169b, Osa-miR1432, Hv-miRx5 and Hv-miR166b/c) were observed between drought-treated and well-watered barley in four genotypes. miRNA targets were predicted using degradome analysis of two, different genotypes, and genotype-specific target cleavage was observed. Inverse correlation of mature miRNA accumulation with miRNA target transcripts was also genotype dependent under drought treatment. Drought-responsive miRNAs accumulated predominantly in mesophyll tissues. Our results demonstrate genotype-specific miRNA regulation under drought stress and evidence for their role in mediating expression of target genes for abiotic stress response in barley.
Publisher: Wiley
Date: 11-04-2019
DOI: 10.1111/PBI.13106
Publisher: Figshare
Date: 2016
Publisher: Figshare
Date: 2017
Publisher: Oxford University Press (OUP)
Date: 11-2007
DOI: 10.1093/JXB/ERM347
Publisher: CSIRO Publishing
Date: 2013
DOI: 10.1071/FP12329
Abstract: Tolerance to boron (B) toxicity in barley (Hordeum vulgare L.) is partially attributable to HvNIP2 , an aquaporin with permeability to B, as well as to silicon, arsenic and germanium (Ge). In this study, we mapped leaf symptoms of Ge toxicity in a doubled-haploid barley population (Clipper × Sahara 3771). Two quantitative trait loci (QTL) associated with Ge toxicity symptoms were identified, located on Chromosomes 6H and 2H. These QTL co-located with two of four B toxicity tolerance loci previously mapped in the same population. The B toxicity tolerance gene underlying the 6H locus encodes HvNIP2 , whereas the gene(s) and mechanisms underlying the 2H locus are as yet unknown. We provide ex les of the application of Ge in studying specific aspects of B toxicity tolerance in plants, including screening of wheat (Triticum aestivum L.) and barley populations for altered function of HvNIP2 and related proteins. In particular, Ge may facilitate elucidation of the mechanism and gene(s) underlying the barley Chromosome 2H B tolerance locus.
Publisher: American Physical Society (APS)
Date: 04-03-2015
Publisher: Elsevier BV
Date: 05-2000
Publisher: Frontiers Media SA
Date: 2014
Publisher: Figshare
Date: 2011
Publisher: Public Library of Science (PLoS)
Date: 23-05-2017
Publisher: Springer Science and Business Media LLC
Date: 28-05-2014
DOI: 10.1007/S00122-014-2322-Y
Abstract: Genetic analysis of the yield and physical quality of wheat revealed complex genetic control, including strong effects of photoperiod-sensitivity loci. Environmental conditions such as moisture deficit and high temperatures during the growing period affect the grain yield and grain characteristics of bread wheat (Triticum aestivum L.). The aim of this study was to map quantitative trait loci (QTL) for grain yield and grain quality traits using a Drysdale/Gladius bread wheat mapping population grown under a range of environmental conditions in Australia and Mexico. In general, yield and grain quality were reduced in environments exposed to drought and/or heat stress. Despite large effects of known photoperiod-sensitivity loci (Ppd-B1 and Ppd-D1) on crop development, grain yield and grain quality traits, it was possible to detect QTL elsewhere in the genome. Some of these QTL were detected consistently across environments. A locus on chromosome 6A (TaGW2) that is known to be associated with grain development was associated with grain width, thickness and roundness. The grain hardness (Ha) locus on chromosome 5D was associated with particle size index and flour extraction and a region on chromosome 3B was associated with grain width, thickness, thousand grain weight and yield. The genetic control of grain length appeared to be largely independent of the genetic control of the other grain dimensions. As expected, effects on grain yield were detected at loci that also affected yield components. Some QTL displayed QTL-by-environment interactions, with some having effects only in environments subject to water limitation and/or heat stress.
Publisher: Springer Science and Business Media LLC
Date: 10-2000
Publisher: Oxford University Press (OUP)
Date: 25-05-2017
DOI: 10.1104/PP.17.00372
Publisher: Springer Science and Business Media LLC
Date: 11-2001
Abstract: Three allelic forms of barley beta-amylase (Sd1, Sd2H and Sd2L) exhibit different thermostability and kinetic properties. These differences critically influence the malting quality of barley varieties. To understand the molecular basis for the different properties of these three allelic forms, Sd1 and Sd2L beta-amylase cDNAs were cloned, and the effects of the amino acid substitutions between them were evaluated by site-directed mutagenesis. The results showed that an R115C mutation is responsible for the difference in kinetic properties. This substitution resulted in an additional hydrogen bond which may create a more favourable environment for substrate-binding. The different thermostabilities of the beta-amylase forms are due to two amino acid substitutions (V233A and L347S), which increased the enzyme's thermostability index T50 by 1.9 degrees C and 2.1 degrees C, respectively. The increased thermostability associated with these two mutations may be due to relief of steric strain and the interaction of the protein surface with solvent water. Although both V233A and L347S mutations increased thermostability, they affected the thermostability in different ways. The replacement of L347 by serine seems to increase the thermostability by slowing thermal unfolding of the protein during heating, while the replacement of V233 by alanine appears to cause an acceleration of the refolding after heating. Because the different beta-amylase properties determined by the three mutations (R115C, V233A and L347S) are associated with malting quality of barley variety, a mutant with high thermostability and substrate-binding affinity was generated by combining the three preferred amino acid residues C115, A233 and S347 together. A possible approach to producing barley varieties with better malting quality by genetic engineering is discussed.
Publisher: Springer Science and Business Media LLC
Date: 2007
Publisher: Springer Science and Business Media LLC
Date: 16-06-2009
DOI: 10.1007/S00122-009-1080-8
Abstract: Rye is a diploid crop species with many outstanding qualities, and is important as a source of new traits for wheat and triticale improvement. Rye is highly tolerant of aluminum (Al) toxicity, and possesses a complex structure at the Alt4 Al tolerance locus not found at the corresponding locus in wheat. Here we describe a BAC library of rye cv. Blanco, representing a valuable resource for rye molecular genetic studies, and assess the library's suitability for investigating Al tolerance genes. The library provides 6 x genome coverage of the 8.1 Gb rye genome, has an average insert size of 131 kb, and contains only ~2% of empty or organelle-derived clones. Genetic analysis attributed the Al tolerance of Blanco to the Alt4 locus on the short arm of chromosome 7R, and revealed the presence of multiple allelic variants (haplotypes) of the Alt4 locus in the BAC library. BAC clones containing ALMT1 gene clusters from several Alt4 haplotypes were identified, and will provide useful starting points for exploring the basis for the structural variability and functional specialization of ALMT1 genes at this locus.
Publisher: Springer Science and Business Media LLC
Date: 14-01-2010
DOI: 10.1007/S10142-009-0153-8
Abstract: Previous work identified the wild barley (Hordeum vulgare ssp. spontaneum) accession CPI-71284-48 as being capable of limiting sodium (Na(+)) accumulation in the shoots under saline hydroponic growth conditions. Quantitative trait locus (QTL) analysis using a cross between CPI-71284-48 and a selection of the cultivated barley (H. vulgare ssp. vulgare) cultivar Barque (Barque-73, a moderate Na(+) excluder) attributed the control of the Na(+) exclusion trait from CPI-71284-48 to a single locus on the short arm of chromosome 7H, which was named HvNax3. The locus reduced shoot Na(+) accumulation by 10-25% in plants grown in 150 mM NaCl. Markers generated using colinearity with rice and Brachypodium, together with the analysis of introgression lines and F(2) and F(3) families, enabled HvNax3 to be mapped to a 1.3-cM interval. Genes from the corresponding rice and Brachypodium intervals encode 16 different classes of proteins and include several plausible candidates for HvNax3. The potential of HvNax3 to provide a useful trait contributing to salinity tolerance in cultivated barley is discussed.
Publisher: The Optical Society
Date: 08-10-2010
DOI: 10.1364/OL.35.003417
Publisher: AIP Publishing
Date: 27-02-2017
DOI: 10.1063/1.4977432
Abstract: We demonstrate magnetically controlled refraction of a spatial soliton forming beam at the interface between an isotropic material and a uniaxial nematic liquid crystal, in which the optical axis together with an incident beam can make any desired angles with the interface. Depending on the direction of the applied magnetic field and incident beam angle, the refracted soliton forming beam experiences either positive or negative refraction.
Publisher: Figshare
Date: 2017
Publisher: Elsevier BV
Date: 09-2013
Publisher: Springer Science and Business Media LLC
Date: 24-09-2017
Publisher: The Optical Society
Date: 11-02-2008
Abstract: We study the angular momentum (AM) of the arbitrary superposition of counterpropagating paraxial beams that have the same magnitude of the wavenumber. We derive compact analytical expressions for the total AM in a transverse cross section (linear AM density) and the total AM flux through the cross section. We demonstrate that whereas for the time-averaged linear AM density its separation into the spin and orbital parts is not, generally, observed, the total time-averaged AM flux is separated into well-identifiable spin and orbital constituents. Moreover, we show that such a flux is also naturally separated into the fluxes of forward- and backward-propagating beams.
Publisher: Elsevier BV
Date: 03-2013
Publisher: Oxford University Press (OUP)
Date: 15-07-2015
DOI: 10.1093/JXB/ERV320
Publisher: Springer Science and Business Media LLC
Date: 2004
Publisher: Figshare
Date: 2016
Publisher: Springer Science and Business Media LLC
Date: 12-11-2013
DOI: 10.1038/SREP03194
Publisher: Springer Science and Business Media LLC
Date: 25-11-2020
DOI: 10.1038/S41586-020-2947-8
Abstract: Genetic ersity is key to crop improvement. Owing to pervasive genomic structural variation, a single reference genome assembly cannot capture the full complement of sequence ersity of a crop species (known as the ‘pan-genome’ 1 ). Multiple high-quality sequence assemblies are an indispensable component of a pan-genome infrastructure. Barley ( Hordeum vulgare L.) is an important cereal crop with a long history of cultivation that is adapted to a wide range of agro-climatic conditions 2 . Here we report the construction of chromosome-scale sequence assemblies for the genotypes of 20 varieties of barley—comprising landraces, cultivars and a wild barley—that were selected as representatives of global barley ersity. We catalogued genomic presence/absence variants and explored the use of structural variants for quantitative genetic analysis through whole-genome shotgun sequencing of 300 gene bank accessions. We discovered abundant large inversion polymorphisms and analysed in detail two inversions that are frequently found in current elite barley germplasm one is probably the product of mutation breeding and the other is tightly linked to a locus that is involved in the expansion of geographical range. This first-generation barley pan-genome makes previously hidden genetic variation accessible to genetic studies and breeding.
Publisher: Springer Science and Business Media LLC
Date: 23-01-2016
DOI: 10.1007/S11103-015-0427-6
Abstract: The γ-clade of class I homeodomain-leucine zipper (HD-Zip I) transcription factors (TFs) constitute members which play a role in adapting plant growth to conditions of water deficit. Given the importance of wheat (Triticum aestivum L.) as a global food crop and the impact of water deficit upon grain yield, we focused on functional aspects of wheat drought responsive HD-Zip I TFs. While the wheat γ-clade HD-Zip I TFs share significant sequence similarities with homologous genes from other plants, the clade-specific features in transcriptional response to abiotic stress were detected. We demonstrate that wheat TaHDZipI-3, TaHDZipI-4, and TaHDZipI-5 genes respond differentially to a variety of abiotic stresses, and that proteins encoded by these genes exhibit pronounced differences in oligomerisation, strength of DNA binding, and trans-activation of an artificial promoter. Three-dimensional molecular modelling of the protein-DNA interface was conducted to address the ambiguity at the central nucleotide in the pseudo-palindromic cis-element CAATNATTG that is recognised by all three HD-Zip I proteins. The co-expression of these genes in the same plant tissues together with the ability of HD-Zip I TFs of the γ-clade to hetero-dimerise suggests a role in the regulatory mechanisms of HD-Zip I dependent transcription. Our findings highlight the complexity of TF networks involved in plant responses to water deficit. A better understanding of the molecular complexity at the protein level during crop responses to drought will enable adoption of efficient strategies for production of cereal plants with enhanced drought tolerance.
Publisher: Springer Science and Business Media LLC
Date: 20-10-2020
DOI: 10.1038/S41467-020-19183-0
Abstract: Igniting and guiding electrical discharges to desired targets in the ambient atmosphere have been a subject of intense research efforts for decades. Ability to control discharge and its propagation can pave the way to a broad range of applications from nanofabrication and plasma medicine to monitoring of atmospheric pollution and, ultimately, taming lightning strikes. Numerous experiments utilizing powerful pulsed lasers with peak-intensity above air photoionization and photo-dissociation have demonstrated excitation and confinement of plasma tracks in the wakes of laser field. Here, we propose and demonstrate an efficient approach for triggering, trapping and guiding electrical discharges in air. It is based on the use of a low-power continuous-wave vortex beam that traps and transports light-absorbing particles in mid-air. We demonstrate a 30% decrease in discharge threshold mediated by optically trapped graphene microparticles with the use of a laser beam of a few hundred milliwatts of power. Our demonstration may pave the way to guiding electrical discharges along arbitrary paths.
Publisher: Figshare
Date: 2011
Publisher: Springer Science and Business Media LLC
Date: 08-07-2012
DOI: 10.1007/S00122-012-1927-2
Abstract: A large proportion of the worlds' wheat growing regions suffers water and/or heat stress at some stage during the crop growth cycle. With few exceptions, there has been no utilisation of managed environments to screen mapping populations under repeatable abiotic stress conditions, such as the facilities developed by the International Wheat and Maize Improvement Centre (CIMMYT). Through careful management of irrigation and sowing date over three consecutive seasons, repeatable heat, drought and high yield potential conditions were imposed on the RAC875/Kukri doubled haploid population to identify genetic loci for grain yield, yield components and key morpho-physiological traits under these conditions. Two of the detected quantitative trait loci (QTL) were located on chromosome 3B and had a large effect on canopy temperature and grain yield, accounting for up to 22 % of the variance for these traits. The locus on chromosome arm 3BL was detected under all three treatments but had its largest effect under the heat stress conditions, with the RAC875 allele increasing grain yield by 131 kg ha(-1) (or phenotypically, 7 % of treatment average). Only two of the eight yield QTL detected in the current study (including linkage groups 3A, 3D, 4D 5B and 7A) were previously detected in the RAC875/Kukri doubled haploid population and there were also different yield components driving grain yield. A number of discussion points are raised to understand differences between the Mexican and southern Australian production environments and explain the lack of correlation between the datasets. The two key QTL detected on chromosome 3B in the present study are candidates for further genetic dissection and development of molecular markers.
Publisher: Springer Science and Business Media LLC
Date: 07-1999
Publisher: Elsevier BV
Date: 02-2008
Publisher: Elsevier
Date: 2007
Publisher: American Association for the Advancement of Science (AAAS)
Date: 30-11-2007
Abstract: Both limiting and toxic soil concentrations of the essential micronutrient boron represent major limitations to crop production worldwide. We identified Bot1 , a BOR1 ortholog, as the gene responsible for the superior boron-toxicity tolerance of the Algerian barley landrace Sahara 3771 (Sahara). Bot1 was located at the tolerance locus by high-resolution mapping. Compared to intolerant genotypes, Sahara contains about four times as many Bot1 gene copies, produces substantially more Bot1 transcript, and encodes a Bot1 protein with a higher capacity to provide tolerance in yeast. Bot1 transcript levels identified in barley tissues are consistent with a role in limiting the net entry of boron into the root and in the disposal of boron from leaves via hydathode guttation.
Publisher: Elsevier
Date: 2020
Publisher: MDPI AG
Date: 21-04-2021
DOI: 10.3390/IJMS22094348
Abstract: Genetic ersity, knowledge of the genetic architecture of the traits of interest and efficient means of transferring the desired genetic ersity into the relevant genetic background are prerequisites for plant breeding. Exotic germplasm is a rich source of genetic ersity however, they harbor undesirable traits that limit their suitability for modern agriculture. Nested association mapping (NAM) populations are valuable genetic resources that enable incorporation of genetic ersity, dissection of complex traits and providing germplasm to breeding programs. We developed the OzNAM by crossing and backcrossing 73 erse exotic parents to two Australian elite varieties Gladius and Scout. The NAM parents were genotyped using the iSelect wheat 90K Infinium SNP array, and the progeny were genotyped using a custom targeted genotyping-by-sequencing assay based on molecular inversion probes designed to target 12,179 SNPs chosen from the iSelect wheat 90K Infinium SNP array of the parents. In total, 3535 BC1F4:6 RILs from 125 families with 21 to 76 lines per family were genotyped and we found 4964 polymorphic and multi-allelic haplotype markers that spanned the whole genome. A subset of 530 lines from 28 families were evaluated in multi-environment trials over three years. To demonstrate the utility of the population in QTL mapping, we chose to map QTL for maturity and plant height using the RTM-GWAS approach and we identified novel and known QTL for maturity and plant height.
Publisher: Oxford University Press (OUP)
Date: 2009
Publisher: The Optical Society
Date: 12-2010
Publisher: Elsevier BV
Date: 02-2007
DOI: 10.1016/J.TPLANTS.2006.12.002
Abstract: It is generally recognized by geneticists and plant breeders alike that there is a need to further improve the ability to capture and manipulate genetic ersity. The effective harnessing of ersity in traditional breeding programmes is limited and, therefore, it is vital that meiotic recombination can be manipulated given that it plays a pivotal role in generating ersity. With the advent of a wider range of genomics technologies, our understanding of meiotic processes should increase rapidly. Although comparative genetics has been useful, particularly in the broader grass family, the development of physical maps, long-range sequencing and transcript profiles promises to unravel the complexities of genomes as large or larger than wheat. Highlighting the most significant findings to date, this review pools the knowledge on these tools and reproductive processes.
Publisher: Frontiers Media SA
Date: 08-02-2019
Publisher: Springer Science and Business Media LLC
Date: 12-2012
DOI: 10.1038/NBT.2440
Publisher: Springer Science and Business Media LLC
Date: 2000
Publisher: Springer Science and Business Media LLC
Date: 04-10-2019
DOI: 10.1007/S00122-019-03454-6
Abstract: Genetic control of grain yield and phenology was examined in the Excalibur/Kukri doubled haploid mapping population grown in 32 field experiments across the climatic zones of southern Australia, India and north-western Mexico where the wheat crop experiences drought and heat stress. A total of 128 QTL were identified for four traits: grain yield, thousand grain weight (TGW), days to heading and grain filling duration. These QTL included 24 QTL for yield and 27 for TGW, showing significant interactions with the environment ( Q * E ). We also identified 14 QTL with a significant, small main effects on yield across environments. The study focussed on a region of chromosome 1B where two main effect QTL were found for yield and TGW without the confounding effect of phenology. Excalibur was the source of favourable alleles: QYld.aww - 1B.2 with a peak at 149.5–150.1 cM and QTgw.aww - 1B at 168.5–171.4 cM. We developed near isogenic lines (NIL) for the interval including QYld.aww - 1B.2 and QTgw.aww - 1B and evaluated them under semi-controlled conditions. Significant differences in four pairs of NIL were observed for grain yield but not for TGW, confirming a positive effect of the Excalibur allele for QYld.aww - 1B.2 . The interval containing QYld.aww - 1B.2 was narrowed down to 2.9 cM which corresponded to a 2.2 Mbp genomic region on the chromosome 1B genomic reference sequence of cv. Chinese Spring and contained 39 predicted genes.
Publisher: The Optical Society
Date: 24-05-2012
DOI: 10.1364/OL.37.001934
Publisher: Springer Science and Business Media LLC
Date: 11-10-2017
DOI: 10.1007/S10142-016-0526-8
Abstract: Drought is one of the major abiotic stresses reducing crop yield. Since the discovery of plant microRNAs (miRNAs), considerable progress has been made in clarifying their role in plant responses to abiotic stresses, including drought. miR827 was previously reported to confer drought tolerance in transgenic Arabidopsis. We examined barley (Hordeum vulgare L. 'Golden Promise') plants over-expressing miR827 for plant performance under drought. Transgenic plants constitutively expressing CaMV-35S::Ath-miR827 and drought-inducible Zm-Rab17::Hv-miR827 were phenotyped by non-destructive imaging for growth and whole plant water use efficiency (WUE
Publisher: Springer Science and Business Media LLC
Date: 23-02-2016
DOI: 10.1007/S00122-016-2689-Z
Abstract: Study of three interconnected populations identified 13 maturity QTL of which eight collocate with phenology genes, and 18 QTL for traits associated with adaptation to drought-prone environments. QTL for maturity and other adaptive traits affecting barley adaptation were mapped in a drought-prone environment. Three interconnected doubled haploid (DH) populations were developed from inter-crossing three Australian elite genotypes (Commander, Fleet and WI4304). High-density genetic maps were constructed using genotyping by sequencing and single nucleotide polymorphisms (SNP) for major phenology genes controlling photoperiod response and vernalization requirement. Field trials were conducted on the three DH populations in six environments at three sites in southern Australia and over two cropping seasons. Phenotypic evaluations were done for maturity, early vigour, normalized difference vegetation index (NDVI) and leaf chlorophyll content (SPAD), leaf waxiness and leaf rolling. Thirteen maturity QTL were identified, all with significant QTL × environment interaction with one exception. Eighteen QTL were detected for other adaptive traits across the three populations, including three QTL for leaf rolling, six for leaf waxiness, three for early vigour, four for NDVI, and two QTL for SPAD. The three interlinked populations with high-density linkage maps described in this study are a significant resource for examining the genetic basis for barley adaptation in low-to-medium rainfall Mediterranean type environments.
Publisher: The Optical Society
Date: 25-03-2009
DOI: 10.1364/OE.17.005743
Abstract: We suggest a novel approach in all-optical trapping employing a photophoretic force for manipulation of absorbing particles in open air. We demonstrate experimentally the robust three-dimensional guiding, over the distances of a few millimeters, of agglomerates of carbon nanoparticles with the size spanned from 100 nm to 10 microm, as well as their acceleration up to velocities of 1 cm/sec. We achieve stable positioning and guiding of particles as well as simultaneous trapping of a large number of particles in a dual-beam optical trap created by two counter-propagating and co-rotating optical vortex beams.
Publisher: Springer Science and Business Media LLC
Date: 2010
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.PLANTSCI.2015.01.008
Abstract: Mapping of quantitative trait loci associated with levels of in idual metabolites (mQTL) was combined with the mapping of agronomic traits to investigate the genetic basis of variation and co-variation in metabolites, agronomic traits, and plant phenology in a field-grown bread wheat population. Metabolome analysis was performed using liquid chromatography-mass spectrometry resulting in identification of mainly polar compounds, including secondary metabolites. A total of 558 metabolic features were obtained from the flag leaves of 179 doubled haploid lines, of which 197 features were putatively identified, mostly as alkaloids, flavonoids and phenylpropanoids. Coordinated genetic control was observed for several groups of metabolites, such as organic acids influenced by two loci on chromosome 7A. Five major phenology-related loci, which were introduced as cofactors in the analyses, differed in their impact upon metabolic and agronomic traits with QZad-aww-7A having more impact on the expression of both metabolite and agronomic QTL than Ppd-B1, Vrn-A1, Eps, and QZad-aww-7D. This QTL study validates the utility of combining agronomic and metabolomic traits as an approach to identify potential trait enhancement targets for breeding selection and reinforces previous results that demonstrate the importance of including plant phenology in the assessment of useful traits in this wheat mapping population.
Publisher: Springer Science and Business Media LLC
Date: 02-05-2017
DOI: 10.1038/S41598-017-01211-7
Abstract: Soil salinity results in reduced productivity in chickpea. However, breeding for salinity tolerance is challenging because of limited knowledge of the key traits affecting performance under elevated salt and the difficulty of high-throughput phenotyping for large, erse germplasm collections. This study utilised image-based phenotyping to study genetic variation in chickpea for salinity tolerance in 245 erse accessions. On average salinity reduced plant growth rate (obtained from tracking leaf expansion through time) by 20%, plant height by 15% and shoot biomass by 28%. Additionally, salinity induced pod abortion and inhibited pod filling, which consequently reduced seed number and seed yield by 16% and 32%, respectively. Importantly, moderate to strong correlation was observed for different traits measured between glasshouse and two field sites indicating that the glasshouse assays are relevant to field performance. Using image-based phenotyping, we measured plant growth rate under salinity and subsequently elucidated the role of shoot ion independent stress (resulting from hydraulic resistance and osmotic stress) in chickpea. Broad genetic variation for salinity tolerance was observed in the ersity panel with seed number being the major determinant for salinity tolerance measured as yield. This study proposes seed number as a selection trait in breeding salt tolerant chickpea cultivars.
Publisher: Wiley
Date: 26-01-2009
Publisher: Canadian Science Publishing
Date: 12-2008
DOI: 10.1139/G08-084
Abstract: High soil boron (B) constitutes a major soil problem in many parts of the world, particularly in low-rainfall areas and land under irrigation. Low accumulation of B in the shoot or grain of cereal crops is correlated with the maintenance of biomass production and grain yield under high B conditions, suggesting that this trait is an important component of field tolerance. A novel screening protocol to measure B accumulation in aerated and supported hydroponics was validated using a set of known and exotic bread wheat ( Triticum aestivum L.) and durum wheat ( Triticum turgidum L. subsp. durum (Desf.) Husn.) accessions. Furthermore, B accumulation in two Triticum urartu Tumanian ex Gandilyan and 54 Triticum monococcum L. accessions was measured and showed considerable phenotypic variation. However, B accumulation in these lines was higher than that observed in the most tolerant durum or bread wheats. Mapping of high B tolerance in the durum population AUS14010/Yallaroi revealed a locus possibly allelic to Bo1, a major source of B toxicity tolerance previously identified in bread wheat. Here, we show that the Bo1-specific codominant PCR marker AWW5L7 is predictive of B tolerance status among exotic durum and bread wheat accessions. All tolerant durum accessions assayed carried very similar AWW5L7 marker fragments, indicating wide distribution of this allele among tolerant durum wheats. Three bread wheat accessions had tolerance that was independent of Bo1 and is probably located on chromosome 4A. These lines represent a valuable genetic resource for B toxicity tolerance breeding in wheat.
Publisher: Wiley
Date: 29-07-2020
DOI: 10.1111/PCE.13819
Publisher: Universitäts- und Landesbibliothek Sachsen-Anhalt
Date: 2015
DOI: 10.25673/1492
Publisher: Springer Science and Business Media LLC
Date: 17-10-2012
DOI: 10.1038/NATURE11543
Abstract: Barley (Hordeum vulgare L.) is among the world's earliest domesticated and most important crop plants. It is diploid with a large haploid genome of 5.1 gigabases (Gb). Here we present an integrated and ordered physical, genetic and functional sequence resource that describes the barley gene-space in a structured whole-genome context. We developed a physical map of 4.98 Gb, with more than 3.90 Gb anchored to a high-resolution genetic map. Projecting a deep whole-genome shotgun assembly, complementary DNA and deep RNA sequence data onto this framework supports 79,379 transcript clusters, including 26,159 'high-confidence' genes with homology support from other plant genomes. Abundant alternative splicing, premature termination codons and novel transcriptionally active regions suggest that post-transcriptional processing forms an important regulatory layer. Survey sequences from erse accessions reveal a landscape of extensive single-nucleotide variation. Our data provide a platform for both genome-assisted research and enabling contemporary crop improvement.
Publisher: Oxford University Press (OUP)
Date: 13-08-2008
DOI: 10.1093/JXB/ERN199
Publisher: Elsevier BV
Date: 2011
DOI: 10.1016/J.TIBTECH.2010.09.006
Abstract: Adoption of new breeding technologies is likely to underpin future gains in crop productivity. The rapid advances in 'omics' technologies provide an opportunity to generate new datasets for crop species. Integration of genome and functional omics data with genetic and phenotypic information is leading to the identification of genes and pathways responsible for important agronomic phenotypes. In addition, high-throughput genotyping technologies enable the screening of large germplasm collections to identify novel alleles from erse sources, thus offering a major expansion in the variation available for breeding. In this review, we discuss these advances, which have opened the door to new techniques for construction and screening of breeding populations, to increase ultimately the efficiency of selection and accelerate the rates of genetic gain.
Publisher: Figshare
Date: 2016
Publisher: Wiley
Date: 12-2000
DOI: 10.1046/J.1432-1327.2000.01811.X
Abstract: mRNAs encoding a novel thioredoxin were isolated from pollen RNA of Lolium perenne (LpTrx), Hordeum bulbosum (HbTrx), Phalaris coerulescens (PTrx) and Secale cereale (ScTrx). The cDNAs contain a single ORF of 393 bp encoding a protein of 131 amino acids. The predicted proteins showed highest homology to plant thioredoxins of the h class yet form a distinct subgroup that is characterized by a high level of sequence conservation (95.4-97.7% identity). GenBank searches revealed additional members of this subclass in tomato, soybean, rice and pine. LpTrx and PTrx were expressed as recombinant proteins in Escherichia coli and tested for thioredoxin activity. Both proteins displayed typical thioredoxin activity in the nonspecific insulin reduction assay, however, were not reduced by E. coli NADPH-dependant thioredoxin reductase.
Publisher: Wiley
Date: 16-03-2013
DOI: 10.1111/PBI.12056
Abstract: Constitutive over-expression of the TaDREB3 gene in barley improved frost tolerance of transgenic plants at the vegetative stage of plant development, but leads to stunted phenotypes and 3- to 6-week delays in flowering compared to control plants. In this work, two cold-inducible promoters with contrasting properties, the WRKY71 gene promoter from rice and the Cor39 gene promoter from durum wheat, were applied to optimize expression of TaDREB3. The aim of the work was to increase plant frost tolerance and to decrease or prevent negative developmental phenotypes observed during constitutive expression of TaDREB3. The OsWRKY71 and TdCor39 promoters had low-to-moderate basal activity and were activated by cold treatment in leaves, stems and developing spikes of transgenic barley and rice. Expression of the TaDREB3 gene, driven by either of the tested promoters, led to a significant improvement in frost tolerance. The presence of the functional TaDREB3 protein in transgenic plants was confirmed by the detection of strong up-regulation of cold-responsive target genes. The OsWRKY71 promoter-driven TaDREB3 provides stronger activation of the same target genes than the TdCor39 promoter. Analysis of the development of transgenic plants in the absence of stress revealed small or no differences in plant characteristics and grain yield compared with wild-type plants. The WRKY71-TaDREB3 promoter-transgene combination appears to be a promising tool for the enhancement of cold and frost tolerance in crop plants but field evaluation will be needed to confirm that negative development phenotypes have been controlled.
Publisher: Springer Science and Business Media LLC
Date: 20-12-2013
DOI: 10.1007/S00122-012-2015-3
Abstract: Improved mapping, multi-environment quantitative trait loci (QTL) analysis and dissection of allelic effects were used to define a QTL associated with grain yield, thousand grain weight and early vigour on chromosome 3BL of bread wheat (Triticum aestivum L.) under abiotic stresses. The QTL had pleiotropic effects and showed QTL x environment interactions across 21 erse environments in Australia and Mexico. The occurrence and the severity of water deficit combined with high temperatures during the growing season affected the responsiveness of this QTL, resulting in a reversal in the direction of allelic effects. The influence of this QTL can be substantial, with the allele from one parent (RAC875) increasing grain yield by up to 12.5 % (particularly in environments where both heat and drought stress occurred) and the allele from the other parent (Kukri) increasing grain yield by up to 9 % in favourable environments. With the application of additional markers and the genotyping of additional recombinant inbred lines, the genetic map in the QTL region was refined to provide a basis for future positional cloning.
Publisher: Springer Science and Business Media LLC
Date: 29-02-2012
DOI: 10.1007/S00122-012-1831-9
Abstract: In the water-limited bread wheat production environment of southern Australia, large advances in grain yield have previously been achieved through the introduction and improved understanding of agronomic traits controlled by major genes, such as the semi-dwarf plant stature and photoperiod insensitivity. However, more recent yield increases have been achieved through incremental genetic advances, of which, breeders and researchers do not fully understand the underlying mechanism(s). A doubled haploid population was utilised, derived from a cross between RAC875, a relatively drought-tolerant breeders' line and Kukri, a locally adapted variety more intolerant of drought. Experiments were performed in 16 environments over four seasons in southern Australia, to physiologically dissect grain yield and to detect quantitative trait loci (QTL) for these traits. Two stage multi-environment trial analysis identified three main clusters of experiments (forming distinctive environments, ENVs), each with a distinctive growing season rainfall patterns. Kernels per square metre were positively correlated with grain yield and influenced by kernels per spikelet, a measure of fertility. QTL analysis detected nine loci for grain yield across these ENVs, in idually accounting for between 3 and 18% of genetic variance within their respective ENVs, with the RAC875 allele conferring increased grain yield at seven of these loci. These loci were partially dissected by the detection of co-located QTL for other traits, namely kernels per square metre. While most loci for grain yield have previously been reported, their deployment and effect within local germplasm are now better understood. A number of novel loci can be further exploited to aid breeders' efforts in improving grain yield in the southern Australian environment.
Publisher: Springer Science and Business Media LLC
Date: 06-2006
DOI: 10.1007/S00122-006-0289-Z
Abstract: A set of 111,090 barley expressed sequence tags (ESTs) was searched for the presence of microsatellite motifs [simple sequence repeat (SSRs)] and yielded 2,823 non-redundant SSR-containing ESTs (SSR-ESTs). From this, a set of 754 primer pairs was designed of which 525 primer pairs yielded an licon and as a result, 185 EST-derived microsatellite loci (EST-SSRs) were placed onto a genetic map of barley. The markers show a uniform distribution along all seven linkage groups ranging from 21 (7H) to 35 (3H) markers. Polymorphism information content values ranged from of 0.24 to 0.78 (average 0.48). To further investigate the physical distribution of the EST-SSRs in the barley genome, a bacterial artificial chromosomes (BAC) library was screened. Out of 129 markers tested, BAC addresses were obtained for 127 EST-SSR markers. Twenty-seven BACs, forming eight contigs, were hit by two or three EST-SSRs each. This unexpectedly high incidence of EST-SSRs physically linked at the sub-megabase level provides additional evidence of an uneven distribution of genes and the segmentation of the barley genome in gene-rich and gene-poor regions.
Publisher: Microbiology Society
Date: 1998
DOI: 10.1099/00207713-48-1-279
Abstract: A PCR-based method has been developed that permits both intraspecies differentiation and species identification of yeast isolates. Oligonucleotide primers that are complementary to intron splice sites were used to produce PCR fingerprints that display polymorphisms between different species of indigenous wine yeasts. Although polymorphisms existed between isolates of the same species, the banding patterns shared several lification products that allowed species identification. Importantly, the method was able to distinguish between species of the closely related Saccharomyces sensu stricto yeasts. In two cases where isolates could not be positively identified there was discrepancy between the phenetic and phylogenetic species concept. The method has applications in yeast ecological studies, enabling the rapid grouping of isolates with related genomes and the investigation of population dynamics of strains of the same species.
Publisher: Canadian Science Publishing
Date: 02-2002
DOI: 10.1139/G01-126
Abstract: DNA mismatch repair is an essential system for maintaining genetic stability in bacteria and higher eukaryotes. Based on the conserved regions of the bacterial MutS gene and its homologues in yeast and human, a wheat cDNA homologue of MSH6, designated TaMSH7, was isolated by RTPCR. The deduced amino acid sequence of TaMSH7 shows conserved domains characteristic of other MSH6 genes, with highest similarity to maize MSH7 and Arabidopsis MSH7. TaMSH7 is expressed in meristem tissue associated with a high level of mitotic and meiotic activity, with maximum expression in the reproductive organs of young flower spikes. TaMSH7 is located on the short arms of chromosomes 3A, 3B, and 3D and has been mapped within barley chromosome 3HS. The copy on 3DS is located within the region deleted in the wheat mutant ph2a, which shows altered recombination frequency in the interspecific hybrids. The relationship between the ph2a mutant and TaMSH7 gene function is discussed.Key words: wheat, DNA mismatch repair gene, expression, chromosomal location, Ph2.
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/FP04198
Abstract: Wheat Meiosis 5 (WM5), isolated from an early meiosis anther cDNA library of wheat by cDNA subtraction encodes a novel glycine–serine–proline–alanine-rich protein. The corresponding homologous genes are located on the short arms of chromosomes 3A, 3B and 3D of allohexaploid wheat (Triticum aestivum L.). The copy on 3DS is located within the region deleted in the wheat mutant ph2a that displays increased homoeologous chromosome pairing in crosses with alien species. While WM5 is expressed primarily in young flower buds during early meiosis it is also expressed in shoot meristems, thus indicating functional roles in both meiosis and meristem development. Overall, the WM5 amino acid sequence shares no significant similarity with other known proteins in the NCBI database. However, the carboxyl-terminal region does have similarity with the Arabidopsis PDF1 (Protodermal Factor 1) protein. Comparing WM5 and PDF1 reveals that the two proteins share 33% identity and have similar hydropathy plots and predicted secondary structures. In situ immuno-staining locates the protein to the nuclei of pollen mother cells undergoing meiosis and the epidermal layer of the shoot and flower meristem, including the cell wall and cuticle. We propose that the WM5 protein has a role in shoot and flower development within this economically important cereal crop.
Publisher: Springer Science and Business Media LLC
Date: 2002
Publisher: Springer Science and Business Media LLC
Date: 11-2000
Publisher: Springer Science and Business Media LLC
Date: 11-04-2007
DOI: 10.1007/S11103-007-9157-8
Abstract: Activation tagging, as the result of random genomic insertion of either promoter or enhancer sequences, can produce novel, dominant mutations by over-expression of endogenous genes. This powerful genomics tool has been used extensively in dicot species such as Arabidopsis, while rice is the only cereal for which an equivalent system exists. In this study we describe an activation tagging system in barley based upon the maize Ac/Ds transposable element system. A modified Ds element (UbiDs) containing two maize polyubiquitin promoters, transposed in families derived from multiple independent UbiDs transformants and generated new Ds insertion events at frequencies ranging from 0% to 52% per family. The majority of transposed UbiDs elements activated high levels of adjacent flanking sequence transcription. Transposon-mediated expression was detected in all barley cell and tissue types analysed suggesting that this system is applicable to all aspects of plant development and biogenesis. In addition to transcriptional activation, this system is also capable of generating insertional knockout mutants and a UbiDs inactivated allele of the granule bound starch synthase I gene (waxy) was recovered that lead to reduced amylose accumulation. The recovery and analysis of dominant over-expression phenotypes generated by this system will provide a novel approach to understanding gene function in large cereal genomes where gene redundancy may mask conventional loss-of-function mutations.
Location: Australia
No related grants have been discovered for Peter Langridge.